The bass flute is pitched in C, like the standard flute. Music for the bass flute is written in treble clef. The bass flute is a transposing instrument which plays the note an octave lower than it is written. Until the 1920s, the alto flute was called a “bass flute.” The orchestration for Holst's Planets includes lines for “Bass Flute in G,” which are played today by alto flutes. Against high flutes, which are sometimes called “bass flutes,” play an octave below a high flute and, like high flutes, are typically in G.