To add a video for Johann Sebastian Bach / Prelude and Fugue, for keyboard No. 21 in B flat major (WTC II/21), BWV 890, just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Johann Sebastian Bach / Prelude and Fugue, for keyboard No. 21 in B flat major (WTC II/21), BWV 890