Warthur
Another high-class album from Budgie, this one is a marked improvement from Squawk and opens with the classic Breadfan, which not only influenced Metallica but sounds an awful lot like early Rush - partly due to the power trio instrumentation, partly because singer Burke Shelley's singing voice had at this point developed a falsetto highly reminiscent of Geddy Lee's. Or maybe, since this came out before Rush's debut, it would be more appropriate to say Geddy Lee's falsetto sounds like Burke Shelley's?
Another touchpoint to early Rush is the Led Zeppelin love - see the cover of blues standard Baby Please Don't Go - but Budgie also show the influence of the other giant of early 1970s proto-metal, Black Sabbath, with the doomy In the Grip of a Tyrefitter's Hand. The album isn't quite perfect - in particular, the slow dirge Parents is about two to three times longer than it really needs to be, with its whining vocals and its laid-back, uninspiring classic rock musical backing. Still, on the whole the album is a more than creditable slice of proto-metal with a good claim, considering Breadfan's insane pace, to be a foundational document of speed metal.