“Conducted by data analyst Andrew Powell-Morse, the study looked into 225 songs that have topped pop, country, rock and R&B/hip-hop Billboard charts for three weeks or more. “I turned to the Readability Score,” said Powell-Morse, who used writing-analysis tools such as the Flesch-Kincaid index, a readability test to measure reading difficulty, to determine the average reading level of a section of text.”