Hand a guitar to just about anyone, and they will play the opening riff to “Smoke On the Water.” It’s instinct.

And that is a testament to Deep Purple’s indelible place in music history.In between the hard rock of the late sixties and the heavy metal of the seventies, there are three bands often credited as bridging the gap: Black Sabbath, Led Zeppelin, and Deep Purple.

Machine Head, Deep Purple’s opus, has plenty of bluesy hard rock to keep anyone from calling it a straight-up heavy metal record (see: “Never Before,” the harmonica solo on “Lazy,” the Doors-y chorus of “Space Truckin'”), but plenty of metal conventions are here in fetal form.

The most obvious is the very presence of Ritchie Blackmore, who would leave Deep Purple to form Rainbow with metal legend Ronnie James Dio. His lead work is still rooted in acid blues (think Hendrix), but there are plenty of flashes of his rapid-fire fretwork that would become so imitated in metal circles.

In most groups, Ritchie would be an unmatched scene stealer. But Deep Purple isn’t most groups.

He and organist Jon Lord spar across the entire disc, trading solos and riffs like the entire album is their duet. His overdriven B3 roars as if it itself was set on fire by an idiot with a flare gun (that’s a “Smoke on the Water” reference, if you missed it).

With Blackmore and Lord mostly playing lead lines the entire record, this leaves bassist Roger Glover to hold down the rhythm parts. And he is up for the task. He pushes his amp to the limit, driving a dirty tone that most metal bassists still use as a standard. Drummer Ian Paice may not be name dropped as readily as hard rock legends like John Bonham or Keith Moon, but he is a world-class virtuoso.

For a good look at the ensemble’s chemistry, look no further than the solo section of “Pictures of Home,” where each member demonstrates that they have what it takes to stand next to the master musicians next to them.

And howling above the din, there is Ian Gillan, whose range and vocal control outpaces most of his contemporaries. His timbre is richer than Robert Plant, with far more power behind than Ozzy. His vocal prowess is well-shown throughout the disc, but perhaps no song demonstrates it better than the opener, “Highway Star,” where he howls, growls, and croons through the band’s blistering riffs.

While I had previously heard many of these songs on Made In Japan, which has been part of my collection since the beginning, hearing them in the context of the studio album makes it obvious why this record is so highly regarded among critics and metal fans alike.