treble

Treble comes from Middle English treble, from Old French treble, from Latin triplus, meaning threefold.

Though it now describes the highest musical pitch or the act of tripling something, its root sense was simply 'threefold,' tying it to counting rather than sound.

Treble is a doublet of triple — both descend from the same Latin word triplus, just borrowed into English at different times and through different paths.