In the 15 years since Bruce Springsteen's last visit to Kansas City, both he and rock have endured significant changes. For starters, the Boss underwent two divorces -- one from his first wife, the other from the E Street Band. The former separation is forever pegged to the brilliant 1987 Tunnel of Love, an album that coincided with the marriage but foretold its dissolution. The latter led to work that, unjustly or not, gratified neither critics nor retailers. Then there's rock, which Springsteen defined before it moved on without him. Whatever other ways he's found to express himself -- the languid "Streets of Philadelphia," the dusty folk of Ghost of Tom Joad -- Springsteen knows only one way to rock: He toils. And in the reassembled E Street Band, he has the only workforce over 40 that you wouldn't think of forcing into retirement. Touring for more than a year behind the mixed-bag boxed set Tracks, the reunited E Streeters have been the gospel muscle behind Springsteen's revivalist shows. Whatever emphasis the Tracks songs had when the band set out, there's little doubt that a hits tour has emerged, with all involved appearing rejuvenated. The shows don't reach marathon levels of length and heat anymore, but no one's complaining, especially the folks who sold out the New Jersey Meadowlands for a 15-night stand. We get only one night, but maybe only Springsteen could make $80 feel like a bargain.