As a member of Small Faces, McLagan was known for his distinctive Hammond Organ and Wurlitzer electric piano play in one of the most influential mod bands of the 1960s.
The band later changed its name to Faces and after it split up McLagan went on to tour and record with some of the biggest names in pop music, ranging from The Rolling Stones to country music great Lucinda Williams.
The Faces also included rock greats Ron Wood, Ronnie Lane, Kenney Jones and singer Rod Stewart. The band scored hits in the United States and Great Britain in the 1970s with songs that included "Stay With Me."
Former band mate Jones said "I am completely devastated by this shocking news and I know this goes for Ronnie and Rod as well," according to a post on his official web page said.
McLagan moved to Austin, Texas about 20 years ago and formed the Bump Band. He was a fixture on local radio and the club circuit in a city dubbed "the live music capital of America."
McLagan was scheduled to start a US tour this week, opening for his former label mate Nick Lowe, his website said.
