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 it is.