All hail Uriah Heep, who 40 years ago this month released their landmark album 'Demons and Wizards.'

Even if you weren't there, cast a glance back to the heady, hazy days of the early 1970s for a moment. It was a very inventive time for rock and/or roll music indeed.

From bubblegum glam stompers like Sweet and Slade to high concept art parties thrown by Yes and Genesis, there was a wide menu from which to choose, and Uriah Heep found its own place on that carte du jour.

Core members Mick Box (guitar) and David Byron (vocals) started their musical trek in 1967 as the Stalkers and eventually, in 1970, morphed into what we now know as Uriah Heep, taking their name from a character in Charles Dickens' 'David Copperfield.'

With the release of their debut album, 'Very 'eavy, Very 'umble' (self-titled on the US release), their trademark was clear: dynamic vocals backed by loud guitars and keyboards. With a blueprint shared by bands like Deep Purple and Vanilla Fudge before them, Heep added in elements of progressive rock and a bit of flight and fantasy to make a mix all their own.

'Salisbury' and 'Look At Yourself' would follow, and although the trifecta of albums was solid, it wasn't until their fourth effort, 1972's 'Demons And Wizards,' that people began to take notice -- due in large part to a (rare) hit single.

The pile-driver 'Easy Livin'' hit the US top 40 and remains the band's only real American hit, while the album from which it came became an FM-radio favorite with such tracks as 'The Wizard,' 'Rainbow Demon,'  'Traveller In Time' and the LP's final track, 'Paradise/The Earth,' an epic 13-minute journey very much rooted in the early '70s.

The disc made the UK top 20 and earned a gold record in the US, riding the charts to No. 23. The entire album is a classic of its genre and time -- full-on action that saddles right up next to more gentle acoustic moments, with a solid rock groove always front and center. With cover art by Roger Dean (of Yes fame, who also did the art for Heep's 'The Magician's Birthday'), its fantasy-themed gatefold sleeve is very much of the era as well.

These days, the band is still rolling on with founding member Mick Box and longtime bassist Trevor Bolder, who, while Heep was battling those demons and wizards, was busy as a member of David Bowie's Spiders From Mars.

Watch Uriah Heep Perform 'Easy Livin'' Live