By and large, heavy metal fans certainly have longterm memories.

And if you're a band that established themselves in a metal way, by veering a bit too much off the metallic highway, your career may never recover.

But Machine Head seem to be a band that managed to successfully recover from an ill-advised "rap metal detour" (1999's The Burning Red), and have subsequently sworn their allegiance back to headbanging fare, as evidenced by such releases as 2011's Unto the Locust.

The first thing you'll discover about the group's seventh full-length studio effort overall is that it is comprised of only seven tracks.

However, time-wise, it all adds up, as the majority of the tunes stretch past either the six-minute or seven-minute mark.

And something else the listener will discover quickly after sampling a few tunes on Unto the Locust is that Robb Flynn and company have hit upon a formula that they follow throughout, save for one song ("Pearls Before the Swine") -- start off mellow, then bludgeon the listener with full-on metal fury.

Case in point, "Be Still and Know" (and its Judas Priest-esque guitar harmony beginning), "Who We Are" (which starts with children singing), etc.

But it all eventually winds up in the same place -- frantic riffing and hollering, especially on the album-opening "I Am Hell," as well as "Locust" and "This Is the End." Perhaps on their next album, Machine Head will attempt to incorporate some of these beginning-of-the-song-experiments into other spots of tunes, to create some varying sonic textures (à la Metallica back in the day, with such tunes as "Orion," "One," etc.).

But still, it can't be overlooked that 17 years after the release of their debut album (1994's Burn My Eyes), Machine Head is still a force in modern heavy metal, as exemplified by Unto the Locust.