McGregor stayed at Studio One for much of the '70s. He sang lead for groups like Generation Gap and Soul Syndicate, and also recorded off and on as a solo act during the '70s.
In 1975, McGregor converted to Rastafarianism. Still with Studio One and working with Earl "Chinna" Smith, he recorded several classic songs.
In 1981, McGregor scored a huge hit single with "Big Ship," which catapulted him to the front rank of reggae stars in the immediate post-Marley era, along with Dennis Brown and Gregory Isaacs.