the.com/alto

means The lower of the two main female (or higher male) singing ranges, sitting below soprano — also the name for instruments pitched in that same middling-low register.

from From Italian 'alto,' meaning 'high' — which seems backwards until you remember it's short for 'contralto,' literally 'against' or 'counter to' the high voice. The term actually comes from medieval vocal music where it named the part sung just above the tenor, back when 'tenor' (from Latin 'tenere,' to hold) carried the melody and everyone else was arranged relative to it. So alto was 'high' only in comparison to the men below it — a relative title that stuck even as it drifted down the register over centuries of choral reshuffling.