if your not already using VLC media player its a cool tool for practice you can pull any thing into it slow it down speed it up put loops on great for putting Johnny videos on to slow down and see what he is up too.check it out its free to download
VLC is an excellent multi format video/audio player. Lots of good features.
YouTube has too the ability to configure a 0.5x speed that allows to watch and listen to vids without pitch distortion. It’s very useful, although a 0.75x option would be more useful in most cases, since reducing the speed to a half can make the vids too slow (and rendering teachers’ explanations very boring LOL).
Audacity is a great program for free that does this as well as enables you to save the file for transporting to other devices.You can also record yourself in the program as well. Pretty useful for practice.