There are few metal bands that have offered a road map to how it's done over an entire career, but Symphony X have.

Though they began by (heavily) following in the footsteps of Yngwie Malmsteen and Dream Theater, by 2000's V: The New Mythology Suite, they came into their own, creating a solid meld of prog, power, and neoclassical metal that continually pushed their envelope of embracing and employing expert songwriting, arranging, and production techniques.

They also learned how to write and record concept albums without the excess in such endeavors dragging them down.

Strictly speaking, Underworld isn't one of those, but it does loosely follow the path and inspiration of Dante's Inferno.

As a whole, it is every bit as "epic" as that word suggests.

The arrangements are wonderful, Michael Romeo's production and Jens Bogren's mix are stellar, but it's the songwriting and playing that offer the greatest pleasures.

A gorgeous post-classical overture (with a full vocal chorus) gives way to the searing, melodic physicality of "Nevermore," while the title cut finds singer Russell Allen trying out screaming death metal vocals amid a chanted backing chorus, soaring keyboards, chunky guitar chord vamps, and ridiculously fast drumming.

"Kiss of Fire" is another low-register exercise for Allen before he soars back to the top of his trademark range amid a dramatic, dark backing chorus, blastbeats, and a twisted bassline.

The chugging death metal interlude is almost evil before it gives way to guitarist Romeo's most twisted, elaborate solo on the record (he literally shreds throughout).

There are midtempo -- even balladic -- tracks here, too, including "Without You," a mix of modern power metal with retro hard rock.

"To Hell and Back," the set's longest cut at over nine minutes, is something of a midtempo noodler, but its various parts and interludes are never less than interesting -- the pop ("hair") metal hook will raise eyebrows.

“In My Darkest Hour” is dangerously close to speed metal in places, but its circular refrain and power chords anchor it to power metal.

Likewise, "Run with the Devil" has sweeping keyboards underneath the guitars that fill the backdrop, keeping prog at the fore.

The amped-up aggression and heaviness on Underworld, suits them -- even though it took them 20 years to get here.

That newfound sense of physicality is combined with the finest elements of album rock -- in the best '70s sense of the term -- anthemic '80s hard rock, and modern power/prog metal here.

As a result, Symphony X sound reinvigorated, fresh, more vital than ever -- unbound by their own history, but providing a near perfect extension of it.