Origin and history of treble

late 13c., "threefold, composed of three like elements or parts;" c. 1300, "three times, triple;" from Old French treble (12c.), from Latin triplus "threefold" (see triple). In harmonic music, "pertaining to the highest part," by mid-15c. Related: Trebly; trebleness; treblefold "three times as many" (late 14c.).

"multiply (a number) by three, increase (an amount) threefold," early 14c., treblen, from Old French trebler, from treble "triple" (see treble (adj.)). Related: Trebled; trebling.

I recollect once talking with one of the first men in America, who was narrating to me the advantages which might have accrued to him if he had followed up a certain speculation, when he said, "Sir, if I had done so, I should not only have doubled and trebled, but I should have fourbled and fivebled my money." [Capt. Marryat, "A Diary in America," 1839]

"highest part in harmonized music, soprano," mid-14c., from Anglo-French treble, Old French treble "a third part," noun use of adjective (see treble (adj.)). Said to be so called because in early contrapuntal music, the chief melody was in the tenor, and the treble was the "third" part above it (after the alto). The treble clef is that of the soprano or violin.

As "product of multiplication by three, a sum three times greater than a certain other" is from late 14c.; by 19c. extended to various senses involving three objects, layer, forces, scores, etc.