Rod Argent, Russ Ballard, Bob Henrit and Jim Rodford say the event at the Waterside Theatre, Aylesbury, on June 2, marks the end of their live career.
They’ll be joined by Colin Blunstone of The Zombies plus Steve Hogarth and Steve Rothery of Marillion, he Moon Dogs, Danny Prendergast and Jerry Playle.
The show aims to provide rehabilitation equipment for 17-year-old Johnny Beer Timms, who was paralysed from the chest down following a trampoline accident. Johnny’s dad Derik fronts the Moon Dogs.
Argent says: “We’re not just musicians – we’re friends. We’ve seen Johnny grow up, and now we want to see him back on his feet.”