The Ontario Chaffey Community Show Band was founded in 1985 and directed by the late, great R. Jack Mercer.  Our 2025-2026 season celebrates 40 years of outstanding music, continuing to pay tribute to the man who started it all.

Members of the band reside in over two dozen communities in Southern California.  The band rehearses on Monday evenings from 7 to 9:00 p.m. in the Jack Mercer Music Hall (building behind the auditorium) on the campus of Chaffey High School located at 1245 North Euclid Avenue in Ontario, between 4th and 5th Streets.  We always welcome new members, and there are no auditions.  Just stop by, bring your instrument, and sit in, wherever your playing level may be!

We perform monthly free concerts for the community at historic Gardiner Spring Auditorium and the Ontario Town Square Bandshell.  Check out SHOWS page for our performance calendar!  We are able to rehearse and provide music for the community thanks to the very generous support of our Sponsors and Donors including the City of Ontario, Chaffey High School, the Chaffey Adult School, Bellevue Memorial Park, The Mercer Family, The Ovitt Family, and the Ontario Community Foundation.  We're also extremely fortunate to have a wonderful network of volunteers that very generously donate their time and efforts to the band and the community.

During the early years of the Ontario Chaffey Community Show Band, Bill Blanchard arranged tunes for the band and was the associate conductor under Jack Mercer.  From 2004 until 2012, Dr. Petrocelli worked as the associate conductor and arranger for the Show Band.  Beginning the 2013-2014 concert season, Dr. Petrocelli stepped up to the podium as the new director of the Ontario Chaffey Community Show Band, taking over from its legendary founder and director Maestro Jack Mercer.  Show Band tuba player and a former youth band director, David Schaafsma, also became assistant director in 2013.  In 2016 Patrick Arnold joined the Show Band to play saxophone and become an assistant director.  On June 16th, 2025 Dr. Petrocelli retired as the Director of the band to become Director Emeritus of the Ontario Chaffey Community Show Band, and turned his baton over to Patrick Arnold to be the new Director.  Pat then asked David Grasmick, trumpet player in the band and an Emeritus Music Professor from Cal Poly Pomona, to assume his position as one of the assistant directors of the Show Band.