[tzs]

Learning music from recordings (video or just audio) would be so much easy if modern video and audio playback software would bring back the AB repeat function that used to be common on CD players, DVD players, LaserDisc players, and MP3 players.

Why the heck did this largely go away?

[shermantanktop]

Check out Amazing SlowDowner. And AnyTune Pro. Plus lots of yt player websites that allow for looping.

[adrianh]

Check out Soundslice for exactly this. It's great audio/video playback (with slowdown, looping, etc.), with an integrated tab and sheet music editor. So you can write down what you've figured out, and it remains synced with the original audio.

[bonoboTP]

VLC has it. And Youtube looper wrapper sites too.