It's used to render sheets and audio in Wikipedia articles (I hope this answers several of your questions). Example: https://en.wikipedia.org/wiki/Humpty_Dumpty

It's used to render sheets and audio in Wikipedia articles (I hope this answers several of your questions). Example: https://en.wikipedia.org/wiki/Humpty_Dumpty#Lyrics_and_melody https://en.wikipedia.org/wiki/Humpty_Dumpty#Lyrics_and_melod...