 Fake books that contain only the chords are used by rhythm section performers (notably chord-playing musicians such as electric guitarists and piano players and the bassist) to help guide their improvisation of accompaniment parts for the song.Fake books with only the chords can also be used by "lead instruments" (e.g., saxophone or trumpet) as a guide to their improvised solo performances.Since the melody is not included in chord-only fake books, lead instrument players are expected to know the melody.