Lamb of God/Mastodon

Ashes of the Wake (Epic)/Leviathan (Relapse)

On every score, 2004 has been a great year for metal. The summer saw the best Ozzfest lineup ever crush up to three generations of metalheads at once. Atreyu, Candiria, and Dillinger Escape Plan have released astonishing albums. And this week, two of metal's best new bands are dropping new records.

Virginia's Lamb of God emerged as champions on Ozzfest's second stage, easily stealing the show from headliners Slipknot. Anybody who saw them, or heard 2003's As the Palaces Burn, already knows their power. With Ashes of the Wake, the band has evolved a bit sonically, leavening its headlong fury with some mellow moments (not ballads, but passages within otherwise brutal tracks). The album also features guest guitar from two old-school metal titans: Megadeth's Chris Poland and Testament's Alex Skolnick. But for the most part, Lamb of God has taken the sound it developed on Palaces and upped the ante. Ashes is crisper, more mechanistic, and harder than its predecessor -- it's almost exhausting to listen to. The band's updated Slayer riffs are exciting, but vocalist Randy Blythe is the greatest weapon. His diatribes, sneered as if by a cranked-up auctioneer, leap from the speakers directly into the listener's brain.

Mastodon has some southern rock in its metal, too. Once in a while, the wall of riffage will split open for a second, allowing guitarist Bill Kelliher to subtly steal from Duane Allman. Like Ashes, Leviathan displays an impressive evolution. It's not as monolithic or hard to take as Mastodon's last album, Remission. The sound is cleaner, the instruments better separated in the mix. These are good things; any time drummer Brann Dailor is more clearly audible, that's a big plus. His intricate fills and high-speed pummeling push Mastodon to the front of the post-death-metal pack.