The musical term alto, meaning "high" in (Latin: ), refers to the second highest part of a contrapuntal musical texture and is also applied to its associated vocal range, especially in choral music. More rarely it describes the highest male solo voice type (usually designated countertenor), and it is also the root word of contralto, the lowest standard female voice type. When designating instruments, "alto" likewise can refer either to the corresponding vocal range (alto flute and alto trombone) or to musical role (alto recorder and alto clarinet).

Alto is a musical term that has several possible interpretations.