Alto Flute

The alto flute is a type of Western concert flute, a musical instrument in the woodwind family. It is the next extension downward of the C flute after the flûte d'amour. It is characterized by its distinct, mellow tone in the lower portion of its range. It is a transposing instrument in G and, like the piccolo and bass flute, uses the same fingerings as the C flute.

The tube of the alto flute is considerably thicker and longer than a C flute and requires more breath from the player. This gives it a greater dynamic presence in the bottom octave and a half of its range.

It was the favourite flute variety of Theobald Boehm, who perfected its design, and is pitched in the key of G (sounding a 4th lower than written).

Its range is from G3 (the G below middle C) to G6 (4 ledger lines above the treble clef staff) plus an altissimo register stretching to D♭7. The headjoint may be straight or curved.

British music that uses this instrument often refers to it as a bass flute, which can be confusing since there is a distinct instrument known by that name. This naming confusion originated in the fact that the modern flute in C is pitched in the same range as the Renaissance tenor flute, therefore a lower pitched instrument would be called a bass.