1. The Psychedelic Warlords

The group's fourth studio album, it was the first by a new line-up that included Simon House on synthesizer, Mellotron and electric violin; absent were Robert Calvert, who had previously contributed lyrics, vocals and spoken word interludes, and Dik Mik, who provided electronic effects.

The album's title was a nod to Edvard Grieg's "In the Hall of the Mountain King" and to a Portobello Road cafe called The Mountain Grill (now closed), frequented by the band in the early 1970s. The cover of a derelict spaceship in the mists of an alien lagoon was painted by the band's regular artistic collaborator, Barney Bubbles. The rear cover was by space artist David Hardy.

The record featured hard rockers like "The Psychedelic Warlords (Disappear in Smoke)" and "Lost Johnny" (subsequently recorded by bassist Lemmy's post-Hawkwind band Motörhead and also by co-writer Mick Farren with his band the The Deviants), psychedelia such as the heavily-phased "D-Rider" and "Web Weaver", as well as quieter atmospheric numbers like the instrumentals "Goat Willow", "Wind of Change" and the title track. Side two of the original vinyl LP was bookended by "You'd Better Believe It" and "Paradox", live tracks recorded at the Edmonton Sundown in January 1974, that recalled the 'space jams' of earlier releases.

In the wake of Robert Calvert's departure, lead vocals for the album were performed by Dave Brock, along with Lemmy on "Lost Johnny" and Nik Turner on "D-Rider". The band's line-up would continue to shift during the year. Del Dettmar left prior to the release of Hall of the Mountain Grill to live in Canada, and Alan Powell joined as an additional drummer. Science fiction author and friend of the group, Michael Moorcock, stepped in to read poetry at their concerts.[citation needed]

Jonathan Smeeton (Liquid Len) has stated that Brock specifically wrote "Wind Of Change" for a particular slide sequence he had on the Space Ritual tour (a tree being engulfed by a city, then the city collapsing with the tree remaining).[citation needed]

At the time of the album's release, Simon King stated "The Doremi album lacked production. I wasn't really happy with the Space Ritual either. But the new one - I'm quite pleased with it. I like side one because I think it's something we haven't done before. Yeah - I'm pleased with half of the new album."[1] Lemmy later commented that "For me, this was when the band were at their height. Oh, and I was in the band at the time." (Classic Rock, April 2006), listing it as #3 in "My Top British Rock Albums".