Queen Mary University of London and Imperial College London have computer analysed 17,000 songs from the US Billboard Hot 100 based on Timbre and Harmony data. The conclusions are particularly interesting.
Timbre and Harmony subsets
Timbre and Harmony were divided into 8 subsets (T1 – T8 and H1 – H8):
- T1 = drums, aggressive, percussive
- T2 = calm, quiet, mellow
- T3 = energetic, speech, bright
- T4 = piano, orchestra, harmonic
- T5 = guitar, loud, energetic
- T6 = /ay/, male voice, vocal
- T7 = /oh/, rounded, mellow
- T8 = female voice, melodic, vocal
- H1 = dominant 7th chords
- H2 = natural minor
- H3 = minor 7th chords
- H4 = standard diatonic
- H5 = no chords
- H6 = stepwise chord changes
- H7 = ambiguous tonality
- H8 = major chords, no changes
Between 1960 and 2009 we see a huge drop in the use of H1 (dominant-seventh chords), showing the death of jazz and blues music in these years. These styles use dominant-seventh chords a lot.
H3 (minor-seventh chords) play a dominant role in funk, disco and soul. Between 1967 and 1977, the graphs show a 200% growth for these kind of harmonies.
H6 combines several chord changes that are a mainstay in modal rock tunes and therefore common in artists with big-stadium rock groups like Van Halen, Queen and Kiss. Between 1978 and 1985 are the highlight days of H6.
And then H5 (no chords!) become more frequent in the late 1980s and then rises rapidly to a peak in 1993. This represents the rise of hip hop, rap and related genres. Because of it’s exponential growth this genre H5 + T 3 (energetic, speech, bright) is considered as the main music revolution of the last 50 years.
The 3 genre based revolutions
The researchers feature three major stylistic periods of the past 50 years based on Harmony and Timbre:
- the 1964 SOUL and ROCK revolution
- the 1983 NEW WAVE, DISCO and HARD ROCK revolution while at the same time SOFT ROCK, COUNTRY, SOUL & R‘nB were also dominant
- the 1991 RAP revolution which made any other style look rather unpopular in comparison
What will be the next musical revolution?
You can download the PDF of this study.