Hi List, In the last two weeks, our best Steinway D has been damaged by unauthorized "prepared" piano use twice!  The first occurrance was three weeks ago during our "Clarifest Day" where a guest artist, without permission started banging on the right cheekblock and side of the rim with his fist.  He pounded so hard it knocked loose the cheek screw and was causing a clicking in the upper regesters.  I was called from home to come down to fix it, and fortunately it was indeed only the loose screw. The second time was this week; a student composer used a mallet and banged on the plate and severely bent up several bass damper heads AND strumming the strings with a wire brush.  The stage manager, the professor of composition, and I were not told this was going to take place and this student beleives he is going to demonstrate it again in the same hall and in our smaller recital room that also has a "D".   The assistant stage manager (in charge that evening) SHOULD have stopped the pre-performance rehersal and swapped out the Steinway for our semi- decent Yamaha C-3.   I'm not sure how to prevent the abuse of prepared pianos.  The faculty doesn't seem to care or think about it, except for the piano faculty, of course.   Do I have a right to prevent such use/abuse?  Could I actually step in and stop a performance?  Should I?  How do you all get faculty and students to get this in their fat heads that this behaviour is not OK? He could have cracked the plate!!! Concerned Paul T. Williams