1. : low spirits : melancholy. suffering a case of the blues. 2. : a song often of lamentation characterized by usually 12-bar phrases, 3-line stanzas in which the words of the second line usually repeat those of the first, and continual occurrence of blue notes in melody and harmony.

The blues may involve feelings of sadness, hurt, loneliness, stress or anger that strike at times of difficult life experiences, or they may simply involve upset feelings that linger longer than you'd like. When you have the blues you can still function and you always know you will bounce back.

The main focus of jazz music is the dynamics and improvisations of an ensemble, while blues music is usually centered on a single guitar player/vocalist, and the personal lyrical content of the song. Most jazz tunes are purely instrumental, while a blues song always contains lyrics.