Hello everybody, My students had an opportunity to perform our spring musical in front of the student body. The show went very well with the exception of a maddening issue. We're running 22 body microphones for the show. They are 9 single frequency AT's, 5 AT3000's and 8 Telex frequency agile microphones with clear scan technology. We had periods of maddening feedback and no matter what my TD tried, she couldn't get it to stop. I noticed the following: 1. The feedback happened during large group numbers when there were 15+ characters, and thusly microphones, on stage in close proximity. 2. The feedback happened near our wings (where our monitor speakers are). Any advice what to do to stop it for our opening? I cannot turn down the monitor mix as our piano player is "deaf" and "must be able to hear herself and the singers"... seriously... she'll walk off the set if we turn her monitor system down. Maybe aim that particular monitor mix (we have 2) away from the stage towards only her? Thanks! Tenor.