McKernan was born in San Bruno, California to an R&B DJ. He became a fixture on the San Francisco coffee house scene that spawned the Grateful Dead and their contemporaries, going on to play in every recording incarnation of the band. Over the years Pigpen contributed vocals, Hammond organ, harmonica, percussion and some guitar. His heavy drinking led to severe health problems beginning in 1970, which forced him to perform only intermittently. He joined the band on the Europe '72 tour but had to quit touring upon returning home. He died of a gastrointestinal hemorrhage the following Spring.