Dwayne and Dwight Bosman have been fixtures on the St. Louis jazz scene since they were teenagers, and though the twins could easily have become a novelty act, a footnote to this city's rich jazz history, they've more than made their mark. The Bosmans have collaborated or shared the stage with everyone from Lester Bowie and Fontella Bass to Roy Ayers and Branford Marsalis. Though most deeply indebted to beebop and post-bop, the twins have an experimental side as well: They have infused their sound with soul and funk, connecting with younger generations while working tirelessly in music-education programs. Their love of saxophones — though they play a variety of wind instruments — is best expressed through their complementary but feisty duets. It's a spiritual, wailing sound, deeply rooted in the call-and-response gospel tradition.