Allan would record an album with Tempest, whose music at that time has been compared with earlier work by Cream. One sonic document is a phenomenal live tape which sees him duetting with Ollie Halsall for a BBC in Concert recording. (“That was the last time I ever saw him"). First, though, was Nucleus, through whom passed any number of fine jazz musicians throughout the Seventies. Holdsworth left his mark on this line-up's album ‘Belladonna' with a blistering solo on the track ‘Hectors House'; in truth there is rarely a dud moment on this fine record. With musicians such as Dave McRae, Roy Babbington, Gordon Beck and Trevor Tomkins on board, that's hardly a surprise:
"So they said then OK, this is what this tune is and then I'd play on a couple of the things. Then they asked me to do a couple of gigs with them as a guest, so I did that. And then after that they asked me join the band. I really had a lot of fun with that band - they were good times. They were all great guys - Kari Jenkins, Mike Ratledge, Roy Babbington, John Marshall. It was really good fun".