"Big Jazza" McGlone was played by Robbie Coltrane, but voiced by Scottish blues singer Tam White. This is only where Coltrane is portrayed playing his deceased brother in flashback. When Coltrane appears as main character Danny McGlone, he does his own singing.
Rumours abounded for many years regarding the BBC's failure to repeat the series or release it on DVD, including that the film stock had been destroyed. It transpired that because the lyrics to one rendition of the title song had been changed the BBC's usual music licensing no longer applied. Copyright holder Little Richard requested an exorbitant fee. These issues were eventually resolved.
Before becoming an actor, like his character Danny, Robbie Coltrane studied at Glasgow School of Art. Several scenes are shot in the Mackintosh Building, distinguished by the long, black-framed windows.
John Byrne wrote the role of Danny McGlone with Kevork Malikyan in mind. Coltrane had previously starred in the original production of Byne's play "The Slab Boys".