As explained on MixedInKey
www.mixedinkey.com
it would be great to make an on/off button beside each deck (and also for the stand alone player please!) which is a QUICK filter and only shows the tracks (of the current selected crate + other filters) which are compatible with each other.
That means if I play a track on deck 2 with the key 8A and I press the "key filter button" on deck 2 only tracks will be shown which have the keys 7A, 8A, 8B, 9A.
Multiple keys per field (as used by Rapid Share (
www.mixshare.com) as I can remember) might be supported.