 A choral non-solo contralto may also have a low range down to D3 (thus perhaps finding it easier to sing the choral tenor part), but some would have difficulty singing above E5.In a choral context mezzo-sopranos and contraltos might sing the alto part, together with countertenors, thus having three vocal timbres (and two means of vocal production) singing the same notes.Alto is rarely used to describe a solo voice (except in the case of soloists in choral works), though there is a multitude of terms in common usage in various languages and in different cultures for solo singers in this range.