OSD Lyrics - OSD Lyrics is a lyrics show compatible with various media players.
Epidemic Sound - Website with licensed music to use in youtube videos
Lyrics Plugin - Lyrics Plugin is a piece of software tailored for music fans.
Extreme Music - Production music licensing
EvilLyrics - Automatic lyrics search tool for most modern media players.
Premiumbeat - Premiumbeat.com provides high quality Royalty Free Music.