If you are looking for nice application that displays the lyrics as the song plays and if you love to sing along then there is a really nice application that can turn your system into a karaoke machine.
OSD lyrics displays lyrics of any song that you play through your music player. It automatically downloads the required lyrics from different sources. Just turn it on and you are ready to go.
Most of the time the lyrics will sync well with the songs, but if you find that it is going too fast or too slow, you can change the speed too. You can also change the font size, colors and the postion on your screen.
It is compatible with many Linux players.
OSD lyrics won't launch if a music player is not running. So first launch your music player, then OSD lyrics. However in OSD lyrics preferences, you can choose to auto launch your favorite player.
To download type and run in the terminal:
sudo add-apt-repository ppa:osd-lyrics/ppa
sudo apt-get update && sudo apt-get install osdlyrics