Many dissidents in Communist Czechoslovakia listened to smuggled in, underground music such as The Velvet Underground, which was an influential American rock band, formed in the 1960’s. American artist of Czechoslovak heritage Andy Warhol managed the band and it played at his studio. The Czechs voiced their own dissenting views of the totalitarian regime through bands, such as The Plastic People of the Universe (PPU), formed in 1968 after the Soviet invasion and reversal of Prague Spring’s liberalization period. The PPU were strongly influenced by American song writer Frank Zappa and hired Paul Wilson, an English teacher, to teach them the lyrics of American songs. In 1976, PPU and others were put in prison for disturbing the peace. Their prosecution led dissident Václav Havel and others to write the Charter 77. Two decades later as President, Václav Havel requested, Lou Reed, a founding member of The Velvet Underground, to perform at a White House dinner held in his honor and hosted by President Bill Clinton in 1998.