Blair Batty

All About Mixtures


scherer-organ

Mixtures, not just about power

It is certainly true that adding a mixture to the chorus makes the chorus much brighter and louder. But, depending on how the mixture is designed and voiced, and how it fits with the rest of the chorus, a mixture can make the organ vocal. I don't mean to literally make the organ "speak" words. Instead, by mimicking the formant structure of vowels, mixtures can add a vocal-like color that has powerful musical effects.

Think of it this way: A choir singing a complex canon. If everyone sings on "Mmm", you can't tell the parts apart. But if Sopranos sing "Ee", Altos "Ah", Tenors "Oh", and Basses "Oo", each voice is instantly distinguishable. In the same way, a subtle vocal-like color from the mixtures clarifies the polyphony.

vowels

The Vocal Organ, all about Vowels

When you speak, your mouth emits a complex mix of sound (vowels and consonants), which are assembled into syllables, words and finally speech. Speech actually is made of two simultaneous tones (or more correctly, partials): a low pitched fundamental (about 250-500 hz) plus a higher pitched partial (900-2,300 hz). There are actually more than two partials, but for what we are doing, we only care about the first two partials (in the drawing, its the left two, lower-pitched partials).

Vowels are distinguished not by fundamental pitch, but by higher pitched partial. The fundamental pitch is the note that you sing. A vowel upper partial is not an exact pitch; rather, it is a band of sound.

Approximate center frequencies of vowel upper partial

You can understand speech, because we all have a sort of "perfect Pitch" ability. Under the right conditions, we hear a sound within certain frequency bands, as a vowel. If you want to hear vowels, try slowly whispering these vowels in this order: "U, O, A, E, I". You can hear the vowel, but you also hear a hiss-sound rise in pitch. It's subtle, but it's all you brain needs translate the pitch to a vowel. Our brains are hard-wired for this.

Speech starts with fundamental sound from your vibrating vocal cords (about 250-500 hz), travelling up your vocal tract (throat and mouth cavity), and out your mouth. Of course the fundamental isn't a sine wave; it includes rich background broadband noise. Your vocal tract (throat, mouth cavity, lips and tongue) is a resonator which acoustically selects, filters and amplifies that sound. By moving our lips, jaw and tongue, we tune the vocal tract, creating the partials of the vowel we want.

blockwerk graph

An Organ's Octave Band Analysis

To understand Mixtures, we need to see how they fit into the chorus of an Organ. Fortunately Werner Lottermoser "Orgeln, Kirchen und Akustik" 1983, has made some Octave Band Analysis for us. In the graph at the left of the page, we see his audio spectrums of the famous Schnitger organ in Steinkirchen, Stade.

You'll notice there are about 40 squiggly lines, organized vertically as divisions: HW, BW and Ped. He sampled three adjacent notes simultaniously, to average them out. C, C#, D for the first sample, D#,E, F for the second sample, etc. And each sample is represented by a squiggly line. The squiggly line is the spectrum of those three simultanious notes, summed. So there are 16 spectrums for the Hauptwerk, each consisting of three consecutive notes. He is sampling the Principal chorus, without Trumpet.

I know it sounds confusing, but all that really matters, is that when you look at any spectrums you'll notice there are two humps. The first hump is the 8' stop, and the second hump is the mixture stop. The lower hump acts as a lower partial, the Mixture acts like an upper partial. With a gap between them we've got our vowel. As you go up the keyboard, and up the spectrum lines, we get higher pitched vowels.

To sum up to get a vowel from a played organ note, you need two partials. The first is a bold 8' Principal for the lower partial. The second is a bold mixture for the second partial. It helps of the rest of the chorus is a little reticent. But if you have a chorus where all the ranks are the same loudness, there are no partials sticking out, and no vowel sound.

To be clear, when laying out his mixtures, Arp Schnitger had no idea about vowels. Vowels are a serendipitous happenstance that some modern builders noticed, and decided to exploit.

Why are Vowels Useful in Organ Music?

1. It Enhances Polyphonic Clarity

This is the most critical musical function in contrapuntal music (Bach, Buxtehude). When several independent melodies (voices) play at once in the same register, they blur together. A mixture solves this by giving each part of the keyboard a different harmonic fingerprint.

Think of it like this: A choir singing a complex canon. If everyone sings on "Mmm", you can't tell the parts apart. But if Sopranos sing "Ee", Altos "Ah", Tenors "Oh", and Basses "Oo", each voice is instantly distinguishable.

The organ mixture does this pitch-dependently. The left hand playing a low C will have its mixture reinforce harmonics around 1100 Hz (an "Ah" quality). The right hand playing high C on the same mixture stop will have its reinforced harmonics around 2,250 Hz (an "Ee" or hiss-like quality).

In summary: The mixture acts like an automatic intelligibility filter. It vocalizes each pitch range differently, so the listener's ear can effortlessly follow intertwining melodic lines simultaneously. Without this vowel-formant effect, complex fugues become muddy soup.

Because pipes in Blockwerks (and Renaissance organs) have the same scaling and voicing, and they do not break, the organ sounds almost the same as you play up the keyboard from bass to treble. The left hand sounds like it is playing on top of the right hand, muddying the polyphony.

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2. Differentiation of several keyboards

The "magic line" on my mixture sheet is an arbitrary curve, on which the vowels spread out evenly, over the compass of the keyboard. A Great mixture will typically fall below and touch it, Positiv will be on it and Brustwerk be above it. If you draw an unknown mixture onto a blank mixture sheet, the magic line instantly tells you how the mixture compares.

If you look at the "master sheet" to the right, you will see curved lines labeled "Ped, Gt, Pos, Bw". These lines indicate the center points of Mixtures for keyboard of the organ. A different mixture curve means that each keyboard has a different range of vowels.

Playing a plenum chord on the Great will have a subtle "ah" sound, Pos an "eh", and Bw an "ee" sound. The vowels give each keyboard a characteristic sound, so a listener immediately recognizes a keyboard change. The Mixtures are the most important stop, to provide differentiation of character between the various keyboards.The mixtures make the Positiv brighter sound than the Great, and the Brustwerk sounding the brightest.

In summary mixtures don't just make an organ louder. They contribute a vowel character to the chorus that 1) helps identify which keyboard you are playing on, and 2) where on the keyboard you are playing. The pitch of the mixture determines which vowel you hear. The voicing and scales of the chorus determine how obvious the vowel is.

blockwerk graph

My Mixture Charts

Now, mixture breaks can be difficult to visualize, so I'm going to share the chart (of a hypothetical blockwerk- shown on right) that I graph mixture breaks on. The horizontal scale, from left to right represents the notes of the keyboard, starting a C1 to C61. The vertical scale represents the actual pitch the pipe speaks. The diaginal lines represents each rank of pipes. (Click on the chart to enlarge, blank samples below).

When pipes of a mixture rank get too small, they jump back to a bigger size. That is called a break and is shown on the graph by jumping to a lower diaginal. This graph is a hypothetical blockwerk so there are no breaks.

Mixtures have limits to the pitch they can go. At bottom "C" the biggest rank could be, for example, 1-1/3', defining the lower limit. Then there is the higher limit called the "plafond" (ceiling). When a rank reaches the plafond, it breaks back to start again at a lower pitch. The plafond can, and usually does raise in pitch as you play up the scale. Gothic mixtures had no plafond; the ranks kept getting smaller, until they stopped because they were too small to make.

The "magic line" is an arbitrary reference it use. Good mixtures usually follow the line.

Mixture Files
mixture

Gothic Organs >1400

We don't know much about the old Gothic organs. There exist no playing examples. There are a few written descriptions and paintings. A couple of derelict, empty cases. There are a few cases and ranks of pipes that have been recycled in new Renaissance and Baroque organs.

We can only guess what they would have sound like. Even the biggest Gothic organs only had one casework, one division, one keyboard. The casework was high, wide and shallow, with a flat front and doors to shutter the organ for Lent.

The pipes in a Gothic organ were all principals, with identical voicing and scale. Typically they were a chorus of 8', 4', 3', 2', 1-1/3', 1' and 1/2' ranks. The treble was brilliant, because ranks continued up towards the top, without breaks, until they were too small to make. Because there was no stop control, all ranks spoke all the time. There were no mixtures; or rather, the entire chorus was one indivisible mixture. This made a powerful, brilliant sound that filled the room.

The ancient Blockwerk had doubled ranks. In Renaissance rebuilds, perhaps the doubled 8' and 4' were cut down to make 16' and 8' Bourdons when the blockwerk was taken apart, as done at Oosthuizen, 1521.

There were no Bourdons, flutes or reeds. My guess is that the sound was a pure and brilliant chorus, with little vowel colouration. Vowels consist of a lower and upper partial with a gap between them. You need the gaps, to allow the vowel formant stand out. But the blockwerk always had all ranks speaking, there were no gaps, so no vowel effect.

Renaissance Organs 1475-1600

There exist few Renaissance organs, and they have suffered from repeated modification, rebuilding and revoicing. Renaissance was a time of experimentation and innovation, where new stop actions enabled breaking apart the Blockwerk. The 8', 4, 2-2/3' & 2' were given independance with their own stop knobs. The higher pitched ranks were gathered together to form a Hintersatz (blockwerk of upper pipes), simular to a mixture without breaks.

This was a period of experimentation and many new stops were invented: stopped and open flutes, regals and trumpets. New styles of music, and ways of playing developed, literally evolving into a new kind of organ. The Renaissance organ developed in different ways in different parts of the country. By the Baroque period we had clearly defined national organs, designed, used and sounding different from each other.

But the Renaissance organ chorus with the Hintersatz, was still essentually a blockwerk decompose. It has a simular sound to the Gothic Blockwerk and just like the Blockwerk, and for the same reasons it had no vowel sounds. For vowels, we had to wait for the Baroque Dutch and North/Central German organs. This coincided with the invention of a new kind of Mixture, and bolder 8' Principals.

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Baroque/Classic French Organ, Period 1650-1790

The leading Baroque/Classic French Organbuilders where the Clicquots, Isnard, Dom Bédos and Thierry. The design of the French organ during Baroque/Classical was extremely uniform, throughout the entire long period. The Paris Guild of Organbuilders strictly regulated who could be an organbuilder, what the organs could look and sound like, what stops could be used and how they were made. This gradually lead to a stagnation and decline of French organ building and organ music that didn't revive until Cavaillé-Coll (1811-1899).

A typical French organ is a two manual and pedal organ. The Grand orgue sat in the main case. The console was installed in the lower part of the main case. The second division, The Positiv, was perched on the gallery rail, to the organist's back.

The casework was no longer built with doors. But towers were used to provide more room for the facade pipes, allowing for a narrower, more elegant case.

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Above, you can see a typical Baroque French organ, the 1710 French organ of the Abbatiale of Flône, in the workshop Orgues De Facto in Stavelot. As you can see, the pipes are temporarily removed to facilitate repair. (Photos by Luc De Vos/Facebook?) It was originally placed on a gallery at the back of the church.

To the left, you can see the organist's console area between the main case and the Positiv. Notice the keyboards, the toe-only short pedalboard, and the drawknobs.

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3rd and 4th Keyboards

Any 3rd and 4th keyboards had short compasses for solo sonorities.

Sound of the Baroque French Organ

The French had essentially one plenum, the Plein Jeu. The French Positiv was a minature Grand Orgue, used as the concertino of the French organ.

Whereas the Classical North German Rückpositiv was the equal, but different, partner of the Hauptwerk.

The Plein jeu

This was the standard full principal chorus without the 16' foundation, similar to the blockwerk, (from which it descended). It was the fluty principal plenum, shown below. The "Grand plein jeu" was the same principal chorus, plus the 16' foundation stops, for a grander, deeper sound.

The Plein Jeu is basically a disaggregated Gothic blockwerk, except the mixtures break back at plafonds, instead of the Gothic practice of ascending as high as possible. I suspect the main reason for the French mixture breaks was to prevent the mixture from going too high and becoming screamy.

Grand Orgue Plein Jeu

Positiv Plein Jeu

No reeds, narrow or wide tierces, or flutes (other than the 16’ & 8’ Bourdons) were ever included in the Plein Jeu. There is no separate 2-2/3' rank in the Plein Jeu.

The Classical French organ has only five pipe types:

The ancient Blockwerk had doubled ranks. Perhaps the doubled 16' and 8' were cut down to make Bourdons when the blockwerk was rebuilt in the new way, so were always included in the Plein Jeu. More likely, the Bourdons were included to fill out the gentle 16' & 8' Montres.

Though many ranks were involved and wind pressures relatively high, the chorus sound was not overwhelming, screamy, brilliant, shrill or high pitched; it was very homogeneous. This is the result of wide treble scales, closed toes, and gentle voicing. The Montres were quite gentle, blending into the Plein Jeu. In contrast, the German Principal 8' was powerful, giving a definite 8' pitch basis, and giving a clear pitch reference for listening to polyphonic music. Perhaps the protestant Dutch/Germans needed a powerful 8' Principal unison tone to support massed congregational singing; which the French Catholics didn't need. Mixtures Plafond is the pitch limit reached by the highest pitch rank of a repeating mixture, at the points of repetition. The typical upper limits were: Fourniture at 1/6', Cymbal at 1/8', and Plein Jeu at 1/8'. Classical French mixtures never went into the top octave of a 2' rank (notes #50-61). This is an octave below 1/16', the practical limit of audibility. The highest pitch at low C was 1/4'. The large numbers of ranks filled the spectrum from 16' to 1/8' providing the brilliance needed to fill the large stone buildings and the powerful resultants that supported the gentle Montres. This “filling of the spectrum” precludes the formation of vowel sounds, so common in German organs. The French contrast their clean, vowel-less chorus with the Cornet and its very strong “A” vowel sound. German organs create the vowel format by using fewer ranks, but are strongly voiced and center around a narrow frequency range (upper vowel format). By having mixtures at different pitch ranges in different divisions, each German division has its own vowel character, so each plenum has a different sound.

ascendante

Two French Mixtures, Ascendante

There are two kinds of mixtures in Baroque French organs. With ascendante mixtures, the tonal mass climbs upward from the bass to treble. This is typically done by breaking back by 4ths and 5ths, about once per octave. However, in this example, by Dom Bedos, it only breaks once every two octaves, but it breaks two ranks at the same time.

This is equivalent to the typical octave-break approach, though I find it awkward and obvious. Ascendante mixtures are often used for Fournitures and a good choice for polyphonic music.

horizontal

Two French Mixtures, Horizontal

The Baroque French Horizontal mixture stays in a strictly delimited acoustical range, by using frequent breaks. This is typically done by breaking back by 4ths and 5th, about twice per octave. Classical Cymbales are always Horizontal. Used together with the Fourniture, they fill the lower spectrum and fuse with the 8' and 4'.

Dom Bedos' Mixture Rules

With French organs, the Fourniture and Cymbale were never used apart. Both were used simultaniously as part of the Grand orgue's Plein Jeu. Compare this with German organs where the Fourniture (Gr: Mixture) was used on the Hauptwerk, and the Cymbale (Gr: Scharf) was reserved for the Positiv.

fourniture-c-c

Cavaillé-Coll Romantic Mixtures, Progression Harmonique

By the Romantic French organ period, the universal adaption of homophonic music ended the desire for mixtures to delineate polyphony. So mixtures were largely abandoned, except for the largest organs. The chest space was needed for more 8' stops.

Besides the traditional mixtures, Cavaillé-Coll (1811-1899) devised an extremely ascendant mixture called the Progression Harmonique. It was break-free mixture, simular to a blockwerk! The Progression Harmonique was intended to be used with the Cymbale Harmonique to create a Gawd-awful noise in his biggest organs. This stop is described as a fairly standard type of "harmonic progression" mixture of the time.

Indeed, some of the best sounding Cavaillé-Colls were rebuilds that retained its classical choruses and mixtures.

cymbale-c-c

Cymbale Harmonique

This stop is far more unusual and was a unique experimental creation by Cavaillé-Coll. It is a "progression" that adds ranks as you ascend, but its composition is notable for introducing a tierce (1-3/5') rank in the treble, an element generally avoided in traditional French mixtures at the time.

Fortunately the Progression Harmonique never really caught on, and even Cavaillé-Coll frequently reverted to classical mixtures.

Cavaillé-Coll's Plein Jeu

In the romantic French period, "Plein Jeu" was a stop name. It was the Fourniture and Cymbale on one draw, though both always keeping separate toeboards. Sometimes the Fourniture is erroneously called a Plein Jeu.

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Baroque German Mixtures

With French organs, the Fourniture and Cymbale were never used apart. Both were used simultaniously as part of the Grand orgue's Plein Jeu. But in German organs the Fourniture (Mixture) was used on the Hauptwerk and the Cymbale (Scharf) was reserved for the Positiv. Whereas the Classical North German Rückpositiv was the equal, but different, partner of the Hauptwerk. The use of the lower mixture on the Hauptwerk, and higher Sharf of the Positiv helped differentiate them.

The frequency range of vowel's upper partial almost exactly concides with the range of a 2' stop. Not coincidently, it is also the area of maximum sensitivity of human hearing. Sit down at an organ console and put on an 8' and 2' stop. Now, starting at bottom C, slowly play up chromatically to the top. Besides the 2' sound, you may faintly hear a vowel sound, starting at "ooh" at bottom "c" and sliding vowels, to "ee" at top "c". It can be hard to hear; try whispering the vowels to inform your ear as to what you're listening for. Also, try different stops.

Look at the "Good Great Mixture" chart to the upper-left. The mixture starts at "C1" as 1-1/3', 1', 2/3' and 1/2' ranks at the left side of the chart. It breaks about every octave so that at the right side of the page at topnote "c61" it is 8', 4', 2-2/3' and 2'.

Almost all mixtures end up at "c61" as 8', 4', 2-2/3' and 2'. The upper limit is the top of a 2' at "c61", because the pipes get too small to tune. You shouldn't use the 5-1/3' or anything bigger than 8' or you introduce a 16' resultant tone. A higher pitched mixture needs an extra break or breaks, to not exceed the top of a 2', at "c61". You can judge a mixture by noting when the 2-2/3' enters the mixture.

A mixture stop artificially creates a fixed set of reinforced harmonics, independent of which key you play. That is exactly what a formant does: a fixed frequency region that emphasizes certain harmonics of a variable fundamental. If you design a mixture to strongly reinforce harmonics around, say, 500 Hz and 1500 Hz, it will make any note played on it sound somewhat like a particular vowel, relative to that pitch.

Your brain selects the mid-point of the four ranks of a mixture, to determine the vowel sound. On the "Good Great Mixture" chart, I've drawn the "mid-point vowel line" as a row of "XXXX". I've also written the associated vowels onto that line. So you can see that this great mixture will start at bottom C1 with an "oh", vowel and the tone will gradually transition to "ee" at top C61.

Okay, a division with a Mixture can have a vowel colouration, which changes from dark to bright (Oh - ee) as you play up the keyboard. How does that help? You gain two advantages from vowel colour. Please note that the vowel effect can be subtle; if you voice your chorus like a blockwerk, the vowel effect disappears.

mixture examples

Mixtures, Contemporary examples

I've got a 3-ring binder of several hundred mixture-break graphs. The variety of design seems endless. I've multiple Mixtures from various vintages and schools of organbuilding. There are some bizarre mixture designs, but the most successful mixtures follow simular design. Fortunately, even if you don't understand about mixtures, it is easy to copy someone who does.

My examples are based upon traditional Northern/Central German Baroque designs, and are simular to the work of good modern builders.

You will notice that by going from Mixture/Scharf/Zimbel, the center of each type of mixture is about an octave higher than the previous, so you will hear the next higher vowel. Also, if you play chromantically up the scale, because of the breaks the "brightness" of the tone rises gradually, spreading out the transition from one vowel to the next.

Mixture Loudness

Mixtures should be voiced so that they can be used all the time. If they are so loud that they can only be used at Easter for the last Hymn, they are a waste. I scale and voice the Mixture simular to the 2' Stop. Some people voice the mixture quints softer, or a pipe or two narrower, because they think it makes the mixture "silvery", but I've never found it necessary.

In small rooms, keep it small, use small scales, 17th halving, closed toes and voice gently. Place the mixture at the back of the chest, so it gets blended and diffused by being obscured by the other pipes and distance. The worst thing you can do is place a mixture accross the front of an exposed, Holtkamp-style windchest.

In huge dead buildings it can be difficult to get enough power. You can always get enough power from the bass. Big pipes will get loud enough, if you increase the scale, cutup and wind. But there is only so much you can get out of the small pipes of the Mixture. You can use a treble ascendant scale and cut it up, but you can only increase the scale so much before it gets Cornetty.

Don't try adding more ranks of lower and higher pitch (i.e. 5-6 rank), which would obscure the vowel. A better approach is doubling the ranks: two pipes per rank. Because it is hard to tune more that four ranks at a time, I'd suggest grouping the doubled ranks in a second 3-rank mixture, pitched slightly higher than the main mixture.

Great mixture

Mixtures, for Great, Hauptwerk

At bottom C1, Great mixtures usually consist of 4 ranks (1-1/3', 1', 2/3', 1/2'). Never use a Tierce rank unless you're using a meantone temperment, because the pure Tierce notes will clash with the tempered ones. Four evenly spaced breaks get you from the bottom of the keyboard to the top.

Since pipes smaller than the top note of a 2' aren't practical, the top ranks of a mixture are usually 8', 4' 2-2/3' and 2'. Don't use a 5-1/3' or you'll create a 16' resultant. Four evenly spaced breaks get you from the bottom of the keyboard to the top.

For a smaller Great, try a three rank mixture. Just eliminate the bottom (1-1/3') rank.

Variants

Some people don't like a break between middle "c" and treble "e", because it disturbs the melody. Other people don't like a break in the first 20 notes of the Gt Mixture, as believe the break disturbs the pedal line, when heard thru the Gt-Ped coupler. But these haven't bothered me. You can soften the first and last couple of pipes of every break, to obscure the break.

Great mixture

Mixtures, for Positiv

The center of the Scharf starts about an octave higher in pitch than the Great mixture, but has six breaks, so that it ends up at the same place as the Great at the top of the keyboard. For a small organ, you can use the Scharf for the Great and the Zimbel for the Positiv.

Brustwerk mixture

Mixtures, for Brustwerk

This Zimbel starts at same pitch as the Positiv mixture so it blends better with the BW chorus. But it skips the first break so it's center becomes an octave higher than the Positiv, resulting in a brighter vowel. Like all mixtures, it ends up at the same place as the Great at the top of the keyboard.

There are different types of Brustwerks. Because the Brustwerk pipework is only a couple of feet from the organist's head, the BW can be treated as a miniature division. You could consider it like a box organ, with small scales gently voiced. A single rank Quint 1-1/3' would suffice for mixture. Break the first octave up to 2/3' so it blends better, and break the top octave down to 2-2/3' so it is tuneable.

An alternative is to treat the BW as a Cornet décomposé, which has no use for a Mixture.

In a large organ, the builder may chose to put a small Positiv in the BW position. Sometimes it may even get shutters and strings! Then it may get a Zimbel, and hopefully a detached console...

Swell mixture

Mixtures, Swell

I've already described my approach for Mixtures in Classic organs. But what about romantic Swells? Normally, I treat the Swell as a Positive division with a string and Celeste, plus appropriate Swell reeds.

But in larger organs, especially when rebuilding older romantic organs, I let it stand as a Romantic Swell, without Positiv ambitions. I let it have an 8' chorus (like a Great) with a low pitched Great style mixture. A typical Swell has a Flute chorus, plus strings and reeds. Often the only principal is an 8' Geigen. A low pitched 2' Mixture will help fill in missing lower parts, of the principal chorus.

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Swell Mixtures, Harmonics

An English stop I like to use as a second mixture in a big Swell, is the Harmonics III. I call it "Harmonics" to emphasize that it is not a chorus mixture; it is used only to reinforce the reed chorus (though the English will also call it "Mixture").

It is basically a Tierce, which meshes well with the strong thirds found in reeds. Plus some additional ranks around it, to support it. This is bold, with generous cutups to blend with the reeds.

Shown here is the new Harmonics added by Mander, to their 1998 rebuild of the huge Skinner at Christ Church, Cranbrook, near Detroit, Mi. In the Mander example, all ranks had the same scale, halving on the 18th.

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Not Mixtures

I love Cornets. But they are not a mixture. They are a solo stop made up of a collection of open flute ranks that are harmonically related.

The Sesquialtera is a two rank cornet-like collection of principals. It is made of 2-2/3' and 1-3/5'. It was popular in the meantone Northern German baroque, but avoided now because of the temperment difficulties of the Tierce. Because of its reedy quality, I don't see it as a substitute for a Mixture.

I've heard Sesquialteras being used like a solo Cornet. But if that's how you want to use it, put in a real Cornet III, it works so much better...

There are mixtures with tierce ranks, originally intended for Meantone organs with pure thirds. I don't recommend using tierce ranks in equally tempered chorus mixtures. It's tuning clashes with tempered thirds, muddying the chorus. Tierces should only be used in solo combinations (like Cornets), so they don't clash with the temperment.

Sample Mixtures