It's been said for years that John Cowan was a soul singer in a bluegrass band — New Grass Revival (also known, in certain acoustic circles, as the world's greatest band). He even released an album of soul covers, Soul'd Out.

For 20 years he's earned his reputation as one of the most spectacular, resourceful singers on the acoustic scene; among male vocalists, only Chesapeake's Moondi Klein can touch him in terms of sheer power and vocal range. But in the past, an occasional predilection for hitting every single melody note like some overwrought gospel preacher has overwhelmed Cowan's material.

On his new, self-titled disc, he pares down his vocal approach and combines his diverse tastes and influences into one passionate vision of American music. The result is striking. Warmly produced by Wendy Waldman, the songs are melodic and generally strong, and ballads such as "This River"

(RealAudio excerpt) and "Nothing But the Blues"

(RealAudio excerpt) draw power from Cowan's relative restraint.

The disappointing exception is Merle Travis' classic "Dark as a Dungeon," which gets a rock-style buildup that detracts from the tune's moving simplicity.

That said, Cowan also demonstrates just how exhilarating his forceful tenor can be on the barrelhouse romp "Wichita Way," a fun number cowritten with Fred Koller, and "High Above the Power Lines," an uplifting rock song by Randy Handley.

The sense of longing he brings to "All I Wanna Feel" (RealAudio excerpt) finds its emotional complement in Barbara Lamb's fiddling and Jim Hurst's beautiful finger-picking.

The album opens unexpectedly and loudly with what Cowan describes as a "computerized Motown drum loop," the foundation of "Roll Away the Stone." The addition of mandolin, fiddle, banjo and organ make it a curious mixture of electronic and traditional instruments.

The loose-limbed, vaguely bluesy "Gotta Get Go" (RealAudio excerpt) is definitely not bluegrass, but Sam Bush's precise mandolin playing drives the groove with help from Scott Vestal on banjo. "I Want You To" sounds like R&B pop — harmless, but lightweight. Far superior is the New Grass Revival-style instrumental "Sligo," an invigorating nine-minute workout Cowan co-wrote with Darrell Scott.

The album's thematic root is located in these lines from "Nothing but the Blues," co-written by Cowan and Billy Crain: "Mr. Bill Monroe and old Muddy Waters knew/ What it's like to love and lose/ Now I understand the songs they sing/ 'Cause I've got nothing but the blues."

Inspired by Jim Rooney's book "Bossmen" about Monroe and Waters, it's a slow, jazzy meditation that comes across like a statement of renewed musical purpose.