Gareth performed in many radio broadcasts over the years; mostly in dramas for BBC Radio 4. He also narrated some audiobooks. Audio work that is or was commercially available will be annotated as such on this page.
His earliest documented role on radio was in 1970. Gareth played a character called Jones in episode 4 of a series entitled Battles of Britain. “The Clan” was written by Seamus McGonagle:

Image reproduced with kind permission from Glyn Thomas from a scrapbook compiled by Annie Novac
Sadly, no recording of the above play seems to have survived.
The Goddess of the Mountain is a 15-minute opera by David O’Brien adapted from the traditional Japanese legend. It was originally composed in 1971 and the following year it premiered at the Edinburgh International Festival Fringe, performed by the Y Teenage Opera Group.
It was revised by David in 1984 and recorded with Andy Read as Musical Director.
The cast is as follows: The Hermit: Gareth Thomas; Yosoji: Leo Andrew; Fuji San: Linda Rusby (the future Mrs Gareth Thomas)
Musical credits: Flute: A. Findon; Clarinet: J. Harte; Cello: F. Schaefer; Percussion: T. Wagstaff; Piano: Andy Read
Recording (1984) kindly provided by David O’Brien