By adding two members to Double Trouble -- keyboardist Reese Wynans and saxophonist Joe Sublett -- Stevie Ray Vaughan indicated he wanted to add soul and R&B inflections to his basic blues sound, and Soul to Soul does exactly that. It's still a modern blues album, yet it has a wider sonic palette, finding Vaughan fusing a variety of blues, rock, and R&B styles. Most of this is done through covers -- notably Hank Ballard's "Look at Little Sister," the exquisitely jazzy "Gone Home," and Doyle Bramhall's impassioned soul-blues "Change It" -- but Vaughan's songwriting occasionally follows suit, as well. Even if only the tortured blues wailer "Ain't Gone 'n' Give Up on Love" entered his acknowledged canon, he throws in some delightful soul-funk touches on "Say What!," the instrumental wah-wah workout that kicks off the album, and the Curtis Mayfield-inspired closer, "Life Without You," captures Vaughan at his best as a composer and performer. It's such a seductive number -- such a full realization of his soul-blues ambitions -- that the rest of the album pales in comparison. In fact, for all of its positive attributes, Soul to Soul winds up being less than the sum of its parts, and it's hard to pinpoint an exact reason why. Perhaps it was because Vaughan was on the verge of a horrible battle with substance abuse at the time of recording or perhaps it just has that unevenness inherent in transitional albums. Still, he has good taste in covers, his originals are sturdy, and there's not a bad performance here, so Soul to Soul winds up enjoyable in spite of its flaws, and it clearly points the way to his 1989 masterpiece, In Step.