Lyrics

Lyrics (in singular form Lyric) are a set of words that accompany music, either by speaking or singing. The word 'lyric' derives from the Greek word "lyrikos", meaning "singing to the lyre".
The word lyric came to be used for the "words of a song"; this meaning was recorded in 1829. The common plural predominates contemporary usage. Use of the singular form 'lyric' remains acceptable, yet is considered erroneous in referring to a singular song word as a 'lyric'.
A combination of words when spoken "sung" in a musical fashion would create in the ear of the recipient the combined effect of the sound of a musical instrument in the voice and the delivery of a message in the words which would have a succinct and direct intention to evoke thought or emotion.

From wikipedia.