From the Greek

From the Wordsmith word-a-day list:

gamut (GAM-uht) noun

The complete range of something.

[From Medieval Latin, contraction of gamma ut, from gamma (third letter of the Greek alphabet), used to represent the lowest tone + ut, from the names of the notes ut, re, mi, fa, sol, la, si (ut and si later changed to do and ti). Gamma + ut contracted to gamut and the meaning expanded to denote all notes. The names ut, re, mi, fa, sol, la, si are derived from the initial syllables of a Latin hymn.]