How strange--in a musical climate that gives a new Neil Diamond CD all the promotion in the world, the newly released soul-throwback I Believe To My Soul is already collecting dust. Maybe it's just that this music doesn't yell, "Look at me, I'm important!" but these 13 grooveful tunes are breezy enough to live on one of the Nixon-era LPs that made famous the album's cabal of soul singers. Allen Toussaint and Ann Peebles, both MIA from the studio for a decade, turn in the most indelible tracks: Peebles' "When the Candle Burns Low," an ode to forgiveness recorded here for the first time as a spare Muscle Shoals ballad, and Toussaint's smoothly funky "Mi Amour." Billy Preston's infectious "Both Ways" rings like a lost radio nugget, while Irma Thomas' Hammond-polished version of "Loving Arms," a tune covered by everyone from Elvis to the Dixie Chicks, somehow proves itself definitive on this compilation. Yet no one here sounds better than Mavis Staples on "Keep On Pushing," covering her old collaborator Curtis Mayfield with the same crackle that graced her classics. As with Solomon Burke's 2002 comeback record, Don't Give Up on Me, producer Joe Henry facilitates the proceedings with gimmick-free classic sounds, which doesn't help the hype department. But luckily, one of the most underrated albums of the year is also one of the most unassuming.