What is a “blue note”?

a. the smallest musical interval in the Western major or minor scale; the distance between any two adjacent keys
on the piano
b. a pattern of pitches forming the chromatic scale
c. a discordant mingling of sounds
d. a note that conveys the idea lament or mourning in a melody
e. the three notes in African-American folk music that are typically altered for expressive purposes

ANSWER: e