The Funk Brothers was the nickname of Detroit-based session musicians who performed the backing to most Motown recordings from 1959 until the company moved to Los Angeles in 1972. They are considered one of the most successful groups of studio musicians in music history. The Funk Brothers played on Motown hits such as "My Girl", "I Heard It Through the Grapevine", "Baby Love", "Signed, Sealed, Delivered I'm Yours", "Papa Was a Rollin' Stone", "The Tears of a Clown", "Ain't No Mountain High Enough", and "Heat Wave". The role of the Funk Brothers is described in Paul Justman's 2002 documentary film Standing in the Shadows of Motown, based on Allan Slutsky's book of the same name. The opening titles claim that the Funk Brothers have "played on more number-one hits than the Beatles, Elvis Presley, the Rolling Stones and the Beach Boys combined."