1. State of dejection or gloom.
2. A style of music originating in the mid-nineteenth century from southern African-American secular songs usually featuring a syncopated 4/4 rhythm, flatted thirds and sevenths, a 12-bar structure, and lyrics in a three-line stanza in which the second line repeats the first.
My friends have all left and forgotten me. I've got the blues.
“The blues is an expression of anger against shame and humiliation” (B.B. King).