Brock and Calvert instigated the formation of the Sonic Assassins with Ark members Harvey Bainbridge (bass) (b. Harvey Frederick Bainbridge, 24 September 1949, Dorset), Paul Hayles (keyboards) (born 15 November 1948) and Martin Griffin (drums) (born 1950, Plymouth, Devon died 6 January 2020).
The name Sonic Assassins had originally been coined by Michael Moorcock to describe Hawkwind in a FRENDZ comic strip, 1971.
Sonic Assassins played one gig, at the Barnstaple Queens Hall on 23 December 1977, with a day of overdubs being added some time later at Griffin's studio.
The set was to be released as an album, but it was eventually released only on various EPs and compilations: During Hawkwind's tour of the United States in early 1978, Simon House left to join a David Bowie tour and Paul Hayles filled in as his replacement.
[1] On returning to the UK, Hawkwind were dissolved and resurrected as the Hawklords, with Bainbridge and Griffin forming the rhythm section.