The arid southern Iran province of Bushehr has been traversed by traders from East and West for millennia. All these visitors have made contributions to the region’s distinctive music, which combines elements of Persian, Arab, African, and Indian traditions. Other significant influences include Sufi mysticism and songs about pearl diving in the Persian Gulf, once a common local vocation. Tonight’s performance by Saeid Shanbehzadeh and the Traditional Bushehri Music Ensemble, which is making its first U.S. tour, will mate sinuous Indo-Arabic sounds (made by bagpipes and double clarinet) with African rhythms (played on bass drum and castanets). At 7:30 p.m. at Freer Gallery Steps, 12th & Jefferson Dr. SW. FREE. (202) 357-4880. (Mark Jenkins)