Originally in ancient Greece a lyric was a poem to be sung accompanied by a lyre. There is an interesting example of such a recitation at the beginning of The Odyssey. Now a lyric signifies either a poem expressing personal emotion, or the words of a song.
Editors. "Lyric". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=681, accessed 31 March 2015.]