Alex Clarke Quartet Line Up : Jolyon Jackson [Keyboards], Alex Clarke [n/a], Brian Masterson [Bass Guitar], Roger Doyle [Drums]

Active : 1968 - 1969
Jazz Therapy Line Up : Jolyon Jackson [Keyboards], Chris Hanney [Guitar], Brian Masterson [Bass Guitar], Roger Doyle [Drums]

Active : 1969 - 1969
Supply Demand & Curve Line Up : Greg Boland [Guitar], Jolyon Jackson [Cello, Organ, Piano, Synthesizer & Recorder], Brian Masterson [Bass Guitar], Paul McAteer [Drums], Roger Doyle [Drums]

Active : 1970 - 1977
Paddy Glackin & Jolyon Jackson Line Up : Paddy Glackin [Fiddle], Jolyon Jackson [Cello, Bouzouki, Mandola, Mandolin, Dobro, Guitar, Bass, Harmonica, Bodhrán, Keyboards, Synthesizer, Tambourine, Whistle & Recorder]

Active : 1980 - 1980
Operating Theatre [Mark 1] Line Up : Roger Doyle [Instrumentation], Olwyn Fouere [Vocals]

Active : 1981 - 1981 Note : Initial line up of the band
Operating Theatre [Mark 2] Line Up : Roger Doyle [Instrumentation], Olwyn Fouere [Vocals], Liam Stack [Trombone], Tom Matthews [Film Direction], Jolyon Jackson [Bass Guitar]

Active : 1981 - 1982 Note : Band line up at the time of the release of debut single, 'Austrian'
Operating Theatre [Mark 3] Line Up : Roger Doyle [Instrumentation], Olwyn Fouere [Vocals], Elena Lopez [Vocals], Sean Devitt [Drums]

Active : 198x - 198x Note : Band line up at the time of the release of 'Queen Of No Heart' single
Roger Doyle Line Up : Roger Doyle [Instrumentation]

Active : 19xx