This neat little circuit can play 8 note tunes at any speed you want. You select the notes with 8 trim pots. The speed in selected through a ninth pot. The circuit draws very little power and can be powered by a 9 volt battery, with the addition of a 7805 regulator to power the TTL logic used.
# R1 controls the speed at which the notes are played. R3-R10 control the pitch of those notes.
# The circuit will operate fine on a 9V battery, with the addition of a 7805 regulator to power the TTL logic used.
# The missing pin on U2 is pin 14.