Phil Lesh, bassist and co-founder of the US rock group The Grateful Dead, has died aged 84.

The musician’s official Instagram account said he “passed peacefully this morning”. He was surrounded by his family.

The psychedelic band, which formed in California in 1965, split 30 years later following the death of frontman Jerry Garcia.

Lesh was with them from the beginning – and also joined the group’s other surviving members for a reunion tour of the US in 2003.