ableton live is the best program for this.
it’s main selling point is the fact it treats audio like elastic, and can timestretch (it calls it ‘warping’) very easily. in fact, the program is pretty much based around time stretching. it’s rewire friendly and all that jazz, but it’s also very simple to use. the built in tutorials are pretty good too, considering most programs have a help file that sucks balls.
it’s second main selling point is the fact it’s made for use live, hence why it’s called ableton live. a lot of electronic producers are using this to dj live, and with midi controllers re-create their songs live with flavor.
regardless i can go on forever why it’s one of the best programs out there. go check it out 