Bert William Sommer (February 7, 1949 – July 23, 1990) was an American folk singer, songwriter and actor. He wrote "We're All Playing In The Same Band" at and about Woodstock and his recording peaked at #48 on the Billboard Hot 100 on 12 September 1970. He was briefly a member of baroque-pop group The Left Banke, co-writing and singing lead on the "Ivy Ivy"/"And Suddenly" single in 1967. At Woodstock, Sommer's performance of Paul Simon's "America" received a standing ovation.

Sommer also played Woof in the original Broadway production of Hair in 1969-70 (his hair is on the playbill for Hair) and "Flatbush" of Kaptain Kool and the Kongs on The Krofft Supershow in 1976. He did not reprise the role in the second season.