B is for Brazil, Bang, bikes, boutiques, and bargains. And one more: Be there. HEAR Bang Music Festival What: Duran Duran, Daft Punk, Gnarls Barkley, Modest Mouse, and lots more rock your socks off. Why: You’ve been hungry like the wolf for a lineup like this. When: Sat., 11 a.m.-midnight. Where: Bicentennial Park, 1075 Biscayne Blvd. (866-432-2264). Marisa Monte What: The Brazilian pop songstress sambas into town courtesy of The Rhythm Foundation. Why: It’s todo legal. When: Fri. & Sat., 8 p.m. Where: Gusman Theater, 174 E. Flagler St., Downtown (305-372-0925). DO Critical Mass Bike Ride What: Coast around picturesque Coral Gables with Emerge Miami to promote alternative transportation. Why: You’re a road warrior. When: Sat., 10 a.m. Where: University Metro-Rail Station, 5400 Ponce de Leon Blvd. (305-579-0069). SEE Aura Fashion Show What: The trend-savvy Gables boutique celebrates its fourth anniversary with a peek at new holiday goods. Why: Only Frasier firs can wear tree skirts. When: Fri., 11 p.m. Where: Social Miami at Sagamore, 1671 Collins Ave., Miami Beach. R.S.V.P. to 305-438-9200. BUY M.A.C. and MBCC Women’s Business Council Shopping Benefit What: A $10 donation (for M.A.C. AIDS fund) and a business accessory (for Suited for Success) get you discounts at Leo and Ralph Lauren, plus champagne, chocolate, and mini makeovers. Why: It’s better to give and receive. When: Thurs., 6-9 p.m. Where: M.A.C., 650 Collins Ave., Miami Beach. R.S.V.P. to 305-695-6834.