Melody Perception

Contour

A melody has been described as a dynamic shape in the musical space of pitch and time. The singer can move the melody up or down in pitch, elongate it by slowing it down, condense it by speeding it up, and within broad limits it remains the same melody. Important features of this dynamic shape are its contours of pitch and rhythm—the pattern of relations between successive notes. Beethoven illustrates this at the start of his Fifth Symphony, where the same pitch-and-rhythm contour is repeated at numerous pitch levels and with many different pitch intervals between the two pitches in the pattern. The song “Frère Jacques” in a minor key [+2 +1 −3 0 +2 +1 −3 +3 +2 +2 −4 +2 +2] is still recognizable as “Frère Jacques” (though you can tell that there's something different about it), an effect Mahler uses in his First Symphony. The pattern of ups and downs [+ + − 0 + + − + + + − + +] is important.

Constraints

The human auditory system imposes constraints on melodies. The pitches in melodies must lie within the audible range of frequencies, and, less obviously, must go neither too slow nor too fast. To be easily recognized, familiar melodies must be presented in a range of tempos between about 0.6 notes/second (1,670 milliseconds/note) and 6 notes/second (167 milliseconds/note). Ornamental arabesques and flourishes can go faster (up to about 20 notes/second), but the notes tend to blur into a continuous stream. Phrases in melodies are usually shorter than five or six seconds, fitting easily into our immediate memory buffer for audition.

Other constraints arise from the musical culture. All but perhaps two of the cultures of the world make use of tonal scales—pitch patterns that divide the octave into five, six, or seven pitch categories and establish a hierarchy of pitches in relation to the tonic (in European music, the familiar “do re mi” scale). A culture's melodies will use that culture's pitch categories, and it will be difficult for someone brought up with a different scale system to sing them in tune. Melodies generally move by small steps along the scale, only occasionally leaping across pitch categories, and typically begin and end on the tonic pitch. (See the “Frère Jacques” description earlier. Note that European scale steps are usually one or two semitones apart, never more than three.) Hermann von Helmholtz suggested that people need the landmarks of the scale categories to keep their bearings in tonal space—they show us the way back to the tonic “home base.”

...