I recently saw Bobby McFerrin with the Cleveland Orchestra (actually the CIM Orchestra at Severance Hall). He involved the audience BIG TIME. In fact, at one point, realizing he was among staunch classical music supporters (this was a big $$ benefit concert) he asked the audience to sing an Aria while he improvised. It was unbelievable. There were clearly some professional choral folks out there amongst the jewelry. He also asked some folks to come on stage and help conduct, etc. The CIM Orchestra (Cleveland Institute of Music) is a great collection of young adults from all over the world, and Bobby was clearly impressed. At one point, he asked them to adlib with him and do a few "top forty" classical hits....it was very entertaining, yet obviously unplanned.
I'm not a big Bobby McFerrin fan; nothing against him, just don't own any of his music...I went to support CIM and support the dear friend I went with, but I have to say I was most impressed with his vast knowledge of different types of music, his stage presence, and his wonderful demeanor. It was a great time.