A wonderful tutorial about MPC Live sampling courtesy of Mr. Sam Haskin:
-I basically set up 4 midi tracks and four audio tracks that all point to the same piece of hardware
-each midi/audio track pair is basically for it's own velocity layer
-on each track I have the notes I want to sample drawn out as long as makes sense based on the sample.
-if it's a plucky instrument, shorter notes. if it has full sustain, about a bar or two
-so say I want to sample two notes per octave -- on each midi track I'll place notes at c and f# starting at c-1 and going up to say, c3 or f#3
-some instruments make sense to do more than 2 per octave--bass guitars tend to have more variation within an octave than most synths, so maybe do 4 notes per octave in that case
-but most synth patches you're ok at 2
-so in each track, set the velocity based on the layer. since the MPC only gives you 4 layers, it makes sense to make the velocities in increments of 32 or 33
-where in the scale to do that kind of depends on the patch
-so if it's really touchy, maybe split it out starting at 16 for your lowest layer, sometimes you start at 0, sometimes 32. whatever sounds best and gets you the most range
-it helps to copy the midi clip from track to track, then adjust the velocity for the entire clip. that way each velocity layer has the same timing
-then line all 4 audio clips up in parallel in 4 audio tracks
-now this is where I don't know if live works the same way as logic, but…
-you set a looped region around the first note and export just the looped region, but have it export the tracks separately like you're creating stems
-if you have your audio tracks labeled with it's associated velocity that should come out in the bounced files
-so I'll get 4 files: "c-1 v= 32", "c-1 v=64", "c-1 v=96" and "c-1 v=127”
-worst case you just add a step to name the files as it happens and you do that for each note you want to sample
-so c-1, f#-1, c0, f#0 and so on
-so coming out of that process you should have a sample for each note and each velocity level
-now crack open the MPC
-either standalone or controller mode
-controller is slightly easier, but not horrible in standalone
-the only part that's different really is importing the samples
-in controller, you can just drag them all in together, in standalone you have to add them separately
-so either way, get all the samples you just made into the sample pool
-yeah, there's a little panel that lists out all of the samples in your pool
-you just drag it from the finder into that
-the guy on the right
-from here it's actually easier to do it all on the hardware, either standalone or controller
-so create a new track and select keygroup
-then menu -> program edit
-then click on the samples tab
-oops, one thing first
-in the master tab
-in the top bar you have to set the number of keygroups--basically the number of notes you sampled
-so if you did 2 notes per octave for 3 octaves, that's 6 keygroups
-key groups are basically the the range of keys that a sample will be chromatically applied to
-so for the C samples, they apply to c-f of whatever octave you're in and the f# samples apply to f#-b of whatever octave
-you can see the KG select menu on the master tab
-the trick is basically setting up each keygroup
-so you'll go through the same process for each note you sampled
-but for each key group you then want to go to the samples tab
-in the samples tab you load each velocity layer from lowest to highest
-so once those are loaded you go to the pan/velocity tab
-on that tab you set the start and end velocities for each sample
-so the first one is 0-32, second gets 33-64, etc
-then you set the root note to the actual note of the sample
-the you repeat that for each keygroup
-THEN once you've got all of your keygroups loaded and sounding right on the scale, you go to the filter/env tab
-in the top bar where it lets you select keygroup, select ALL, so you're affecting the envelopes of all of them together
-and from there, tweak the envelope to taste
-and that should be it, then from the software you go to the upper menu and click file -> save current program