As you listen to Wildflowers, Tom Petty's first new album in three years and his first ever for Warner Bros., you may be struck by a certain quality, new for Petty but nonetheless familiar. The predominance of the twangy rhythm guitar; the high-pitched, nasal singing; the irresistibly catchy pop hooks; and the melancholy lyrics straining for a spiritual significance just beyond their grasp--all these elements make Petty sound as if he were a Beatle imitating Bob Dylan. Then you may realize that Wildflowers resembles nothing so much as a George Harrison solo album. That's not such a bad thing; Harrison (Petty's old bandmate in the Traveling Wilburys) has a knack for giving moody spiritualism a pop tunefulness. It's just that Harrison on his own is a second-tier rock & roll figure whose best work is long behind him, and that's pretty much the case with Petty as well. Only with appropriately reduced expectations can one enjoy Wildflowers for what...