Warp engine :
The warp engine allow to puch the records on the desired tempo. It’s a very powerfull tool that works very well for electro music loops. I wanted to make a demo of its use, but ofcourse, there is a lot of good tutorials wich are very good. Here is the compilation.
I’ll make mine (in french) on the specific case of a rock record with a fluctuant tempo, because it is very complex, actually, as it distort the sound.