YouTube Music video doesn't offer music-related feature, like, you can't find information about the artists, lyrics or concert dates. But a simple Greasemonkey script adds the missing feature: lyrics to your YouTube Music video’s. The script creates a container titled "Lyrics" below the video's description and shows the lyrics when you expand the container. Obviously, the video must contain the artist's name and the song's title. If the script doesn't find the lyrics of a song, change the site that provides lyrics (lyrics.astraweb.com seems to be the best) or choose from one the alternative songs.
As usually, to install this script you need Firefox and the Greasemonkey extension.