Although there is scarcely any novelty in bands from yesteryear reforming to give a new audience (and many of the old one) the opportunity to discover their back catalogue, it is still sometimes the case that the ducks line up in a neat row by happenstance to settle some old scores.

Among the great lost combos of Glasgow's musical heritage, the name of Cado Belle is recalled with particular fondness by those who saw and heard them. They made just the one self-named album, released in 1976 on the short-lived Anchor label, but it stands up well as an example of blue-eyed soul funk alongside the work of the Average White Band and London's Kokomo (three of whom guested on the disc in supporting roles).

Cado Belle's frontwoman Maggie Reilly went on to work with Mike Oldfield and is still playing and recording, and guitarist Alan Darby's career has included stints with Eric Clapton and Paul McCartney.

Saxophonist and flautist Colin Tully, who was, alongside keyboard player Stuart MacKillop, one of the group's principal songwriters, went on to write the scores for Bill Forsyth's early films That Sinking Feeling and Gregory's Girl.

After he'd sent that music off to the film-maker – Tully reckons he completed between 45 minutes and an hour's worth, not all of which made the movie's final cut – the composer, still fresh from a music degree at Glasgow University, made a decision that changed his life forever.

While a student he had been introduced to the Alexander Technique, a system of physical awareness and posture control that many musicians and actors find beneficial, and he decided he would learn to become a teacher and practitioner.

"So I turned my back on music as a career," says Tully. "In hindsight it was terrible timing. The Gregory's Girl soundtrack would have opened doors."

However, there is no rancour in Tully's tone. In fact, music has remained a big part of his life. His Celtic jazz group Sensorium, formed with friends in the south-west of England and which takes themes derived from the Scots/Irish tradition and weaves them into a broadly jazz context, will be part of this year's Glasgow Jazz Festival. The programme for their concert at Platform in Easterhouse next Friday will include a 20-minute suite of the music from Gregory's Girl, played in Scotland for the first time.

As it happens, Tully's invitation to perform the movie music in Glasgow has coincided with the reissue of more recordings made by the Cado Belle musicians.

The whole group, including bassist Gavin Hodgson and drummer Davy Roy, backed singer/songwriter Jim Wilkie on his solo disc The Waxer, at Glasgow's CaVa studios in 1978. Wilkie and CaVa's Brian Young have dusted off the old mastertapes and a CD version of the album, reissued on Ridge Records, will be launched at Glasgow's Universal bar on Sunday July 1. Sensorium will also be making an appearance as special guests.

Like Tully, Wilkie turned his back on music shortly after making his only disc, and went on to establish the West Highland Free Press on the Isle of Skye with future Labour MP Brian Wilson.

However, Cado Belle did not quite mark the end of Colin Tully's adventures in the music business. After that group split, he and Maggie Reilly joined an Irish funk group called Stagger Lee. While he was living in Dublin he played on a session with a singer named Johnny Logan on a song called What's Another Year, which went on to win the Eurovision Song Contest in 1980 and got to number one in nine countries.

"I spent three months drinking champagne and hanging around television studios, then moved to Devon to learn the Alexander Technique," Tully recalls.

"I'd had problems of tension, perhaps through playing many different instruments, and I was probably quite screwed up as a teenager. It gave me a way out of that."

These days Tully and his family live near Monmouth and he splits his time equally between teaching music and teaching the technique.

Sensorium play perhaps half a dozen times a year – "We're not interested in playing every gig we are offered" – and he also performs with keyboard player John Paul Gard's Hammond organ trio.

One of his two teenage daughters sings and plays the cello and is, says her father, "very promising" as a songwriter. There are plans for her to make some demos in a gap year, before she goes on to further education. Which, oddly, is very similar to how it all started for Colin Tully and Cado Belle.

Sensorium play the Gregory's Girl Suite at Platform, Easterhouse, Glasgow on Friday June 29, 7.30pm