This graph displays the average word complexity of the top 100 billboard songs over the years from 1960 to 2019. The average word complexity was calculated through a combined score based on analysis of the lyrics. More specifically it is a combination of the diversity of words, the average word length, and the readability (calculated using the Flesch score through the textstat library).

As shown in the graph, the word complexity variability decreases over the years, with a large drop in the 1960's. This large drop in the 1960's may be attributed to cultural shifts; for instance, rock and roll as well as disco became more popular during this time, causing a change in emphasis on lyrical complexity to beat and rhythm. Similar to reasoning for the similarity of word complexity among genres, the relative stability post-1970 may be attributed to a shared song lyric structure for popular songs.