The gradual evolution of pop music from the simple love declarations of 1960 to the pubic mound-thrusting aggressive sex allegories of 2010 has been charted by academics, who claim to have broken down the changes in the world of pop to three significant shifts.
A team from Queen Mary University of London and Imperial College London say there were seismic shifts in the composition of western pop music in 1964, 1983 and 1991, when changes in chord change styles, harmonies and timbres tore up previous music production rule books.
1964 saw the raw rock sound of the Beatles change everything, 1983 was when synth chords and melodies came to the fore, while 1991 was when rap and hip hop emerged as a power in the pop world and tilted everything in its favour for the decades to come.
Dr Matthias Mauch, from Queen Mary University of London, says the 1991 shift is the most significant, explaining: "The third revolution is the biggest. This is so prominent in our analysis, because we looked at harmony -- and rap and hip-hop don't use a lot of harmony. The emphasis is on speech sounds and rhythm. This was a real revolution: suddenly it was possible that you had a pop song without harmony."
Dr Mauch thinks pop music was very nearly killed by the "hair metal" slush of the 1980s, before "hip-hop saved the charts." [BBC]