premise: David Packouz is a musician.
hypothesis: David Mordechai Packouz ( [ pækhaʊs ] born February 16 , 1982 ) is an American former arms dealer , musician , inventor and entrepreneur . Packouz has a cameo in the film as a guitarist and singer at an elderly home . Packouz went on to invent a guitar pedal drum machine , the BeatBuddy , and is currently the CEO of music technology company Singular Sound .