Premise: John Kiffmeyer ( born July 11 , 1969 ) , known professionally in music as Al Sobrante , is an American musician , best known as the former drummer for the punk rock band Green Day . His work with Green Day resulted in about 961,000 albums sold , which are mostly from the compilation album 1,039 / Smoothed Out Slappy Hours .
Hypothesis: John Kiffmeyer is a musician.
Label: ENTAILMENT