OnSong will play the notes of the key of a song without requiring any setup. For instance, if your song is in Am, the notes A, C, and E are played back in a middle octave.
Playing the Pitch
While it's common to hear a pitch played from a pitch pipe before an a capella performance, you can also send the output of your device to the mixing channel of your in-ear monitoring system, or send it as a mono channel to a source board. This setup, like the metronome feature, allows you and your team to hear the pitch without the audience hearing it.