Thanks Alec, you're a gem...
I think the answer for me is going to be to use multiple SD cards - providing I don't drop them and lose them cos they're so tiny!!!
You see I don't use any of the standard rhythms in the KN7000 to play the literally hundreds and hundreds of numbers that go to make up my total play list - they're all special rhythms for specific songs produced by the likes of Neil Blake et al, so I guess my requirements are a little abnormal...
Anyway thanks again for all your help.
Roger M
p.s. I will experiment with all your suggestions though..