How-To Guide from Harmonic-Mixing.com
I have all their software, but I also use a free one from
KeyFinder that tags your files either in an ID3 tag or in the filename. With that one you just have to add the 1A-11B notation as
custom ones that correspond to the actual key and your files are ready for mixing. Club DJs use this to go from track to track in a set mashing without worrying they're gonna ruin it.
It's not a 100% science, but the idea is if you have a song that's in 10A, you can change to an adjacent number or switch the letter, so you can mix something from 9A, 11A or 10B. Since not ever song is using every note in whatever scale it's using, you can usually mix 2 samples and come out with something tonal. The mashup software they have will even warp your tracks into the same tempo so you can test out rhythm and tonality in one shot. It won't give you a good track like they say it will, but it will give you samples to work with really easily. Within 5 minutes on it I'll mash up at least 4 bar phrases from different tracks that work perfectly.
The free one is great for wav loops of individual sounds. I have them all tagged at the beginning of the file name so I just do the harmonic mixing in Ableton and build construction kits in like 5 minutes.
The most trouble you're going to have is with your samples having different swing, but if you really think something has potential just quantize both your samples the same way in Ableton and then either apply the same groove to both or render them to a single sample quantized and try grooves or warp the rhythm on that.
Time stretching can get weird but if you really want it you can warp the attack, sustain and release on individual notes to make it sound
natural.