 in jazz and blues, a blue note (also "worried" notebenward & saker (2003). music: in theory and practice, vol. i, p.359. seventh edition. isbn 978-0-07-294262-0.) is a note sung or played at a slightly lower pitch than that of the major scale for expressive purposes. typically the alteration is a semitone or less, but this varies among performers and genres. ==origins and meaning== the existence of the blue note within music ultimately derives from the fact that equal temperament in western diatonic harmony is an artifice or compromise originally used in the eighteenth century to address problems posed in the creation of keyboard instruments. equal temperament was an artificial 'straightening out' of a tendency for the natural harmonic series (musical intervals as they exist in nature) to go off at a tangent, meaning that higher intervals and octaves in their natural form are of a different pitch than the lower intervals and octaves. this made it difficult to create keyboard instruments that were 'coherent'. hence, the blue note attempts to correct this artifice by playing a note that is closer to the interval as it exists in the natural harmonic series. country blues, in particular, features wide variations from the diatonic pitches with emotive blue-notes. blue notes are often seen as akin to relative pitches found in traditional african work songs. thumb|center|400px|blue notes (in blue): 3, (4)/5, 7  the blue notes are usually said to be the lowered third, lowered fifth, and [[min
Blues Jazz_techniques Musical_notes