Dimension I: spectral energy distribution, from broad to narrow Dimension II: timing of the attack and decay, synchronous to asynchronous Dimension III: amount of inharmonic sound in the attack, from high to none

BN - Bassoon C1 - E flat Clarinet C2 - B flat Bass Clarinet EH - English Horn FH - French Horn FL - Flute O1 - Oboe O2 - Oboe (different instrument and player) S1 - Cello, muted sul ponticello S2 - Cello S3 - Cello, muted sul tasto TM - Muted Trombone TP - B flat Trumpet X1 - Saxophone, played mf X2 - Saxophone, played p X3 - Soprano Saxophone

Reference:

Grey, J.M. (1975). An exploration of musical timbre. Ph.D. dissertation (Dept. of Music Report No. STAN-M-2, Stanford University, CA) (unpublished)