This confirms research done by Joan Serra et al., reported in http://www.reuters.com/article/us-science-music-idUSBRE86P0R820120726 http://www.reuters.com/artic

This confirms research done by Joan Serra et al., reported in http://www.reuters.com/article/us-science-music-idUSBRE86P0R820120726 http://www.reuters.com/article/us-science-music-idUSBRE86P0R... (original paper: http://mtg.upf.edu/system/files/publications/srep00521.pdf http://mtg.upf.edu/system/files/publications/srep00521.pdf). Both analyses show that the music of 1967 was the most varied of the period studied.