Premise: Josef Janíček (born 28 December 1947 in Prague, Czechoslovakia, now Czech Republic) is a Czech rock keyboardist, singer, accordion and guitar player. He was a former guitarist of The Primitives Group; from 1969 he played with The Plastic People of the Universe. He was also a member of Milan Hlavsa's band called "Půlnoc". Since 1990, he is a member of The Velvet Underground Revival Band.
Hypothesis: Josef Janíček is mute.