The basic pitch vocabulary has remained unchanged-the same notes and chords that were popular in decades past are popular today-but the syntax has become more restricted. Similarly, the pitch content of music has shriveled somewhat. That implies a homogenization of the overall timbral palette, which could point to less diversity in instrumentation and recording techniques. Joan SerrГ , a postdoctoral scholar at the Artificial Intelligence Research Institute of the Spanish National Research Council in Barcelona, and his colleagues examined three aspects of those songs: timbre (which вЂњaccounts for the sound color, texture, or tone quality,вЂќ according to SerrГ and his colleagues) pitch (which вЂњroughly corresponds to the harmonic content of the piece, including its chords, melody, and tonal arrangementsвЂќ) and loudness (more on that below).ДЄfter peaking in the 1960s, timbral variety has been in steady decline to the present day, the researchers found. Of the million songs therein, 464,411 came out between 19 and include data on both the sonic characteristics and the year of release.

The researchers based their analysis on the Million Song Dataset, a publicly available 280-gigabyte file that provides a sort of background sketch-name, duration, tempo, and so on-of songs from nearly 45,000 artists. ( Scientific American and Scientific Reports are both parts of Nature Publishing Group.) The findings, published online July 26 in Scientific Reports, show that some trends do emerge over the decades-none of them necessarily good. ItвЂ™s also one way to read a new study on the evolution of pop music in the past half-century.ДЄ group of researchers undertook a quantitative analysis of nearly half a million songs to look for widespread changes in musicвЂ™s character over the years. At least, thatвЂ™s the stereotypical lament of each receding generation of music listeners.

Pitch million song database