Maybe somebody could help me with this...I've noticed one
marimba company mentions that they tune to the "sixth"
overtone ...but most of the other companies say they tune to the "third"
overtone ...Why the difference? Or is there a difference? Greta...

Hi Greta,
Most people confuse the terns "overtone" and "partial".. And then to make matters worse, they confuse "overtones" on a marimba, vibe, etc., with the "overtone series" OR "harmonic series"--same thing..Even companies that claim to tune this or that overtone usually mis-state it..

"Partials" are all the naturally occuring pitches in the overtone series INCLUDING the fundamental. "Overtones" are all the naturally occuring pitches in the overtone series ABOVE the fundamental. These pitches are, in the key of C---c,c,g,c,e,g,b-flat, c etc.... For interesting study on your own, I suggest you look up the overtone series in any book on acoustics..

On a piano string the overtones follow, more or less, the natural overtone series..
BUT, the overtones in a block of wood don't. So instrument makers tune certain overtones intentionally to produce the color and intonation characteristic of a marimba, xylo, etc. On most marimbas, the "partials" that are tuned are the first (fundamental), the 4th - 2 octaves above the fundamental, and the 10th -3 octaves and a major third above the fundamental. (One could also say these are the fundamental, and 3rd and 9th harmonics--are you really confused now?)

Until more recently, the "10th partial was tuned as a MINOR third--a pitch not even occuring in the natural harmonic series..All those old Deagans and many fairly older Mussers have minor 3rds. Several companies have very recently also started tuning other high harmonics...If a company (we won't say which one) claims to be tuning the 6th harmonic, it means they are also tuning a pitch 2 octaves and a minor 7th above the fundamental..
The poiont is, Greta, one can tune almost any harmonic one chooses---well not really---but many different notes could be tuned intentionally...

Before 1926 there were no harmonics tuned. Then the people at Deagan came up with the idea of tuning at least the 4th partial (3rd harmonic) or "double octave". This greatly improved the tonal quality of marimbas as well as the intonation. Before then, many low notes had just accidentally tuned harmonics such as an octave and a minor 7th, octave and major 7th, major and monir 9ths...a pretty terrible sound by modern standards.

Xylophones are a whole different story.. there is one "principal" harmonic tuned which is the 6th partial (5th harmonic) an octave and a perfect 5th above the fundamental.

This is pretty basic information but maybe enough to get your feet wet with.. there are other harmonics that must be taken care of as well--transverse harmonics, torsional harmonics, etc.--most of which are tuned in a way so that they will not INTERFERE with the other pitches...those little "X's" on the back of high xylo bars, or the slits along the side of the same bars...feel under the bars of your marimba in the range between about F4-A#4 (it varies with models)... that "V" shaped arch you feel is one way of dealing with a very difficult transverse harmonic problem that ALWAYS occurs on marimbas.

OK I've got a rehearsal....
I didn't read this over..there may be a couple of inadvertent errors..I hope not..

Bill Youhass
Fall Creek Marimbas