Robert Calvert returned full-time to Hawkwind, following a guest spot with the band at the Reading Festival the previous August. Now consisting of guitarist Dave Brock, saxophonist Nik Turner, drummers Simon King and Alan Powell (the so-called "drum empire"), bassist Paul Rudolph and Simon House on keyboards and violin, Calvert now fronted Hawkwind. With new management in place, they signed to Charisma Records and released their eighth studio album, Astounding Sounds, Amazing Music, in August 1976. True to its title, the album features a more refined and contemporary sound.

Hawkwind's ranks continued to revolve: Dik Mik left the band the previous August, followed by Robert Calvert, who left to record a solo album. Hawkwind returned to the US in March, for their 1999 Party tour, adding Simon House, ex-High Tide and Third Ear Band, on keyboards and violin. The album, Hall Of The Mountain Grill, its title taken from a cafe the band liked to frequent, also gives a nod to the work of classical composer Edvard Grieg.

By the end of 1971, Ian "Lemmy" Kilmister (previously in Sam Gopal), drummer Simon King (previously in Opal Butterfly) and poet Robert Calvert had been thoroughly integrated into the Hawkwind fold. The summer of 1972 saw a surprise hit single for the band: "Silver Machine" b/w "Seven by Seven" rode the UK charts all the way to No. 3, providing the band with bona fide success. The song, sung by Lemmy, was culled from the Greasy Truckers' benefit concert at London's Roundhouse.