In 1963 he joined with Ernest Wilson and Peter Austin to form The Clarendonians, and began to record for the Studio One label. He was only seven years old at the time and was known as ‘Little Freddie’. He was also a member of the Generation Gap.
McGregor worked with producer Niney the Observer during the late 1970s and early 1980s, and in the same period was part of the resurgence of Studio One. His popularity soared in the early 1980s with the release of “Bobby Bobylon”. Other popular hits of McGregor’s include “Big Ship”, “Push Comes to Shove”, “Just Don’t Want to Be Lonely” (a top ten hit in the UK), and “I Was Born a Winner”; as well as cover versions of many early reggae standards. He has also worked with producers Junjo Lawes, Linval Thompson, and Gussie Clarke. McGregor has also recorded as a drummer with artists such as Sugar Minott and Judy Mowatt.