This has been probably caused by a malfunctioning jack on the prerecorded sequences channel. The stage sound guy made the ultimate mistake: putting out the jack and exposing it to the monitors hence causing this unacceptable amount of feedback coming from stage monitors. Get back to what you do best Mark and forget this useless electro music you're doing in the last 8 years. Memories from the acoustic tour in 2010 still lingers on!