An alto is a singer with a vocal range somewhere between a tenor and a mezzo-soprano.

The term is used to refer to the deepest female singing voice, or the highest male voice.

A typical alto will have a range from around the F below middle C on a piano to the D a ninth above middle C.

At the bottom of their range, altos sound almost like a tenor.

In four part choral harmony, the alto is the second highest voice.