A “blue note” in jazz is

a. any note that played with a mute on the instrument
b. a third, fifth, or seventh note of a scale that is lowered one half step while the
accompanying major chord is unchanged
c. a melody note that sounds lower than its accompanying chord
d. a note that singer “slides” the pitch as he or she sings it
e. any syncopated note in the melody

ANS: b.