Pauline,
For live play the SD Card is a definite winner. I have about 100 dance setups so far on the SD Card. When you want to load a song you can set up the KB to either select by Folder (each folder holds 20 selections), or by Title (alphabetical), or by number. I find that the number system is the easiest.
For instance if a particular song is located in folder 22, position 17, you just type in 2217 and you are there - press load and you are up and running in about 3 seconds. In my music book index I simply have the song title followed by the location number. Nothing could be easier or faster.
Regards,
Walt