The Grass Roots band has undergone several changes in musicians since its beginning in 1966. They did not have a keyboard player when they began, but in 1969 lead guitarist Creed Bratton left the group and was replaced by keyboardist and vocalist Dennis Provisor.
Provisor left in 1971 and was succeeded by keyboardist Virgil Weber. Weber left sometime before 1974, and Provisor returned in 1974. The original band disbanded in 1975.
In 1982 the band reformed, and Charles Judge was on keyboard.
In 2000 the group produced an album, and Larry Nelson played keyboard.