Free Baseball Project Show at the House of Blues: If you’re a fan of both rock and roll music and baseball then the Baseball Project is smack dab in the middle of your wheelhouse. Formed in 2007, the “supergroup” is comprised of former Dream Syndicate leader, Steve Wynn, R.E.M. alum, Peter Buck, Minus Five frontman (and former R.E.M. auxiliary gun), Scott McCaughey, as well as, “Mrs. Steve Wynn,” Linda Pitmon on drums and with two volumes of songs titled, “Volume 1: Frozen Ropes and Dying Quails,” and, “Volume 2: High and Inside,” you know they’re not nibbling. On Saturday afternoon the band will give a special free performance in the Foundation Room at the Boston House of Blues conveniently located across Landsdowne Street from Fenway Park between games of the Red Sox-Yankees doubleheader with Buck’s former R.E.M. teammate, Mike Mills, taking his spot in the lineup. They expect to begin between 4:30 and 5 but will need to be done by 7 in order to perform the National Anthem before the 7:15 nightcap. The following day they’ll head out to the cozy confines of Wellfleet’s Beachcomber for a more traditional gig.