Fleetwood Mac co-founder Peter Green died “peacefully, in his sleep,” on Saturday at age 73, according to spokespeople for his family. Green co-founded Fleetwood Mac in 1967 with drummer Mick Fleetwood and guitarist Jeremy Spencer, and later, bassist John McVie. He quit in 1970 and later formed the Peter Green Splinter Group, with which he released nine albums. He and other members of Fleetwood Mac were inducted into the Rock and Roll Hall of Fame in 1998. The group held a tribute concert for Green in February, with guests like Pete Townshend and Steven Tyler.