The alto flute (sometimes called the bass flute – although there is a true bass flute that is used in drum and fife bands) has the same range as the concert flute, but is pitched a fourth lower (in G). Like the clarinet it is one of the transposing instruments - in this case the composer writes the music a fourth higher than it is meant to sound. Its relationship to the “normal” flute is much the same as the viola to the violin.
There is little well known original concert music featuring the instrument. A popular composition by the Japanese film composer Toru Takemitsu, “Towards the Sea”, is scored for alto flute and guitar; and various contemporary composers are using it in ensemble music. It is more often found in transcriptions of music for concert flute or other instruments or in jazz.