The triple threat of REO Speedwagon, Styx and Eddie Money, Wednesday, May 17, at Fiddler's Green, is proof that arena rock never died -- it just spent a decade or so touring the state-fair circuit. In terms of both nostalgia and comedic potential, Wednesday's show is not to be missed, a chance to pull out the old cutoffs and Members Only jackets and rock like you mean it. Speedwagon and Styx, two of the bands in this holy trinity of power rock, have released more than forty albums since 1971 -- a piece -- and all continue to fill stadiums from Japan to Europe. On this tour, original Speedwagon members Kevin Cronin and Neal Doughty reassembled the band by bringing in longtime Speedwagon drummer Bruce Hall and former Ted Nugent guitarist Dave Amato. And as proof that power chords and prog rock spring eternal, Styx has played ninety gigs this year and the band plans to play another hundred before 2001. As for Mr. Money -- he's still shakin', snappin' his fingers, just like always. C'mon, you know you can't fight that feeling anymore.