Dr. Mick Grierson from Goldsmiths, University of London, fed data from fifty of the greatest songs ever recorded into a computer program. The software tore apart each track looking for a recipe of elements that go into making up an iconic song. Beats per minute. Key. Chord variety. Lyrical content. The variety of tonalities and sounds throughout the song. Passages of loudness and softness and the transitions between them. He found that 8o% of the songs were in a major key in this order: A, E, C and G. The average tempo was 125 BPM and most tracks had between six and eight chord changes. He measured something called “spectral flux,” which is described as how the power of a note varies from one to the next. After all the data was crunched, he and his computer concluded that “Smells Like Teen Spirit” ticked the most boxes. It, therefore, is the most iconic song ever –or at least from the 50 tracks that he chose to examine.