@TeamYouTube I know you're experimenting with your music player right now but please allow the music to be slowed down again (doesn't work with Firefox right now). Guitar players all over the world surely would appreciate this!
Appreciate the info. Please send a feedback report directly from YouTube with these steps for us to work on it: https://goo.gl/WdI0BK . While every individual report may not get a direct response, we do review everything and use the details to investigate and fix issues.