How many programs can you have loaded in the 500 at once?

Peoples. I have an MPC 4000 and you can have up to 128 programs loaded into it at once. So for example, on track 1 - I am sequencing sounds in "Drum Program", track 2 - "Bass Program", track 3 - "Funk Program" etc.

How many programs can you have playing in the MPC500 at once?

I hope that I am explaing myself clearly enough.

You can load/create 128 programs at once since O.S. version 1.13 (the latest).

You can assign 48 programs per sequence, since there are (only) 48 tracks on the MPC500.

Snerg