Surely its the choice of the organiser of the event, let the dj's know what they can or can't play ie ovo, 2nd issues,cd etc. I have a mixture (no cd's) but will ask what is acceptable and stick to what they have requested. Simple. I have only been collecting for 2 years so my collection was a mixture to start with, but as time has gone by I do my best to buy ovo (cash permitting). KTF