The Rolling Stones once claimed that it's "the singer, not the song" that matters, although plenty of dinosaur rock & roll acts wish to disprove that theory. Journey famously found success with two different singers after the band and frontman Steve Perry went their separate ways. Now, a pair of classic-rock lifers comes to town without its well-known singers but with a boatload of well-loved songs. Chicago managed to chart a number of soft-rock ballads after the departure of Peter Cetera; singer/bassist Jason Scheff takes those high parts on "If You Leave Me Now" and "Feelin' Stronger Every Day." Like Chicago, the Doobie Brothers was blessed with several featured vocalists, though none more beloved than local icon Michael McDonald. The blue-eyed soul man said goodbye to his Brothers a long time ago, but that hasn't stopped that long train from running.