[3][4] Under the influence of artists such as Little Richard, Elvis Presley, Chuck Berry and Otis Redding, he became one of the founding members of Nazareth in 1968.

[9][10] He elaborated on the specifics of the health issues and the state of his situation in an interview with the UK music magazine, Classic Rock.

He said that his chronic obstructive pulmonary disease (COPD) that has "worsened in recent years" had made him leave the stage in Switzerland in late August 2013 after only three songs, indicating that, "You don’t know when it's going to come on, but suddenly you can't breathe."

McCafferty also revealed that another health problem was responsible for his onstage collapse at a concert in Canada in July 2013 – a burst stomach ulcer.

"[citation needed] Although McCafferty retired from performing, Nazareth fans can still hear his voice on their 2014 album Rock 'n' Roll Telephone.

[20][21][22][23] Tributes were paid by rock musicians Brian Johnson and Axl Rose, both of whom mentioned him as an influence on their own singing.