Once a song has been entered by the user, a link to a separate page of statistical analysis appears, which automatically provides charts of pitch, duration, and chord distributions, as well as multiple means for representing their transition rates. For instance, in “Strawberry Fields Forever”, the range of pitches in each section tell a clear story:
Notes in the verse strongly emphasize the tonic note (indicated by the lowest grey horizontal bar) , while the melody in the chorus opens up to an entire octave between the fifth (top grey bar, repeated at bottom). By restricting the note range in the verse, Lennon increases tension which is released by the wider melodic range in the chorus.
In fact, pitch range is widest for the three most common chords in popular music, the I, IV and V (these classic chords constitute, for instance, almost every Elvis Presley song). On the other hand, minor chords in the key (iii and vi) and unusual chords (minor v and VI) are almost always in a lower range. Lennon builds up the tension in the unusual chords using lower pitches, which release on the stronger I, IV, and V at higher notes.
The automated analysis can also show us how notes lead to each other in this song. For instance, consider the 12 chromatic notes of the octave arranged in a circle, with lines connecting them based on how often they appear next to each other in the melody.
Many popular melodies emphasize step-wise motion in the melody, so it is not surprising that many of the lines in the above graph skirt the circle. When they jump across, we see that Lennon outlines the tonic chord based on the I, 3, and 5. In fact, most tellingly is that the 5 is a launching point for all other non-diatonic tones. Many lines emanate from this pint towards unusual notes like the flat-2, flat-7, and even the flat-5. This is partly why his unusual melodies are able to hang together, because they are well-anchored to more common notes in the scale.
“Strawberry Fields Forever” is copyright 1967 Northern Songs Limited. Words and music by John Lennon and Paul McCartney.