The UA Percussion Ensembles and guest percussionist Bob Becker present "A World of Percussion: Five Concerts in Five Days." Thursday, April 19, at 7:30 p.m.: Graduate Percussion Quartet. Friday, April 20, at 7:30 p.m.: Rosewood Marimba Ensemble. Saturday, April 21, at 7:30 p.m.: UA Percussion Group. Sunday, April 22, at 3 p.m.: UA Steel Bands. Each concert is $5 at the door. Monday, April 23, at 7:30 p.m.: World Music Gang, Centennial Hall, 1020 E. University Blvd.; free. Call 621-1162 for more information.