After Saturday night's show at Jones Beach, it's clear there is a good reason why heavyweights of rock the Doobie Brothers and Chicago tour together. Both big-league players in the '70s and early-'80s music scenes, the Doobie Brothers' soul-tinged rock and Chicago's easy, head-bobbing beats draw a hefty following. While the Doobie Bros' band members have been shuffled like a deck of cards, leaving only originals Tom Johnston and Patrick Simmons, the prolific rockers were in fine form. Equally as enticing were the nine current members of Chicago, who, after having undergone their fair share of band-member scrambling as well, more than lived up to expectations with a solid set. TONY photographer Bill Kelly captured the tour buddies' performance.