Xylophones are sets of objects (generally bars -steel in my case) of varying lengths that accordingly produce varying pitches (longer=lower).
youtube playlist of anarchestra xylophones
The primary decisions a xylophone builder is presented with are about selecting and ordering the pitches and what degree of muting or sustain is desired.
The mathematics of xylophones is pretty simple.
If a given length produces a tone (say D)
a bar .9715 of that length will produce a tone a chromatic step higher (say D-sharp)
a bar 1.0293 of that length will produce a tone a chromatic step lower (say D-flat)
assuming the bars of the same thickness and width. Thicker bars produce higher pitches.
To mount the bar without deadening it the ideal place (called the node) is 22% in from each end of the bar.
The timbre of the bar is largely determined by the performer’s choice of striker —a softer mallet produces a slower attack and stronger low overtones and a harder one will produce a faster attack and stopnger high overtones.
Some Anarchestra xylophones:
Pig 00 Chilmark
Chromatic, low to high left to right, 1/4″ x 1 1/2″ bars
Kyzyl Kum 02 Chilmark
Chromatic, high to low left to right, 1/8″ x 1 1/2″ bars.
An octave lower than Pig.
Sir Gamelan 01 Chilmark
A tongue drum with 3/16 plate
Bootzilla 06 Santa Fe
Random order 1/8″ x 1/2″ bars
Bootz 08 Tucson
Chromatic, low to high, (seen from side) front to back, 1/8″ x 3/4″ bars
Kresge 10 Tucson
Chromatic, low to high, high to low, high to low, low to high front to back, 3//16″ x 1″ bars
X-why? 11 Tucson
Diatonic, ordered in thirds, 1/8″ x 1″ bars
Louie Trey 12 Tucson
Chromatic, grouped in threes root-fifth-octave, minor thirds front to back, chromatic steps side to side, 1/8″ 3/16″ 1/4″ x 1″ bars
Gamagang 12 Tucson
Chromatic, made from 7″ steel steps
Forky 14 Tucson
Diatonic, low to high front to back, minor thirds left to right, 1/8″ 3/16″ 1/4″ x 1/2″ bars
Chewbewler 16 Tucson
Chromatic, random order 16ga x 1″ tubes
Reboot 17 Tucson
Bass xylophone with 8 keys than can be replaced and ordered in different ways.
Bith 17 Tucson
3/4 by 1/2 inch bars allow different pitches or both to be played.