Founded by celebrated Jacksonville jazz drummer Ulysses Owens Jr. and his family in 2008, the nonprofit organization Don’t Miss a Beat (DMAB) has helped more than 20,000 local youths find a positive groove in life through music and arts programs throughout the Brooklyn, Riverside, and Woodstock neighborhoods.  DMAB is presenting a jazz event from 1-11 p.m. on Saturday, July 23 …