Take it from Mike Barna of North Olmsted, Ohio: When you’re composing, the muse can appear in many different forms—including, as Barna found out, as objects as inanimate and abstract as the calendar on the wall. “It was Friday the 13th recently, so I decided to compose a little lick in the spirit of the ominous date,” says Barna of his submission below. “The phrase alternates between 7/8 and 6/8—two time signatures that combine to equal 13/8—thereby putting the number 13 to use rhythmically. And the three sextuplets in bar 2 add a nice, evil ‘6-6-6’ to the mix. Tap [T] notes where indicated and play the rest of the notes legato using hammer-ons and pull-offs.”