Music that is extremely angular--be it avant-garde jazz, avant-garde rock or avant-garde classical--has a way of intimidating those who expect quick or immediate gratification from recordings.

Some of the most hardcore jazz enthusiasts in the world have had a hard time getting into Ornette Coleman (just to give one example), which is regrettable because Coleman's music has a lot to offer listeners who are not frightened away by his angularity and complexity.

Big doses of angularity have also been known to frighten away headbangers if a metal band is ultra-technical, and there is no getting around the fact that Dark Deceiver is a highly technical contribution to progressive metal.

Zero Hour has many of the usual power metal and prog-metal influences one would expect a prog-metal band to have, including Iron Maiden, Fates Warning, Judas Priest and Dream Theater.

But Dark Deceiver, although melodic, is much more angular and much more technical than anything those bands have offered.

While more accessible prog-metal bands like Dream Theater and Rhapsody have had their share of infectious grooves, Dark Deceiver is seldom groove-minded.

Instead, Zero Hour keep things very cerebral--and while this 44-minute CD isn't full-fledged math metal, it certainly doesn't shy away from the abstract either.

But those who aren't intimidated by all that angularity will find that this 2008 release is definitely worthwhile.

The material, although not exceptional, is generally solid--and Zero Hour's uncompromising outlook is admirable.

Dark Deceiver finds Zero Hour adamantly sticking to their guns 15 years after their inception.