a few have my mates who play kinda deeper, minimal techno (sorry for using that word) have started getting the key of tunes and keeping track of them. so for every 3% change on the pitch slider constitutes a semitone change. then they got a list of aesthically 'nice' note changes from some forum or other and play tracks in a certain order.
they are adiment that this can help with mixing tracks, but im a bit dubious of it to say the least. from what i can gather, its more to do with making them as Djs, feel a bit more 'intellectual' as performers
my argument to them was, you mix records that go well together anyway, or should, so in that sense you utilise some level of internal harmony.... instead of going by a set of rules.
and even if you accepted this as a good process, why if you are on a key of 'C' should your next track be in 'G' and not B flat or something.
could this be restricitve or a good idea?