Based on a study of their most popular songs:
Pop songs have become angrier and sadder over the past 60 years, experts say.
Researchers analysed lyrics in best-selling songs from the 1950s to 2016 to find expressions of anger and sadness had increased, while words about joy had dropped.
The US study team looked at lyrics of more than 6,000 songs from Billboard Hot 100 in each year.
These are the most popular songs in the US each year as chosen by music fans.
Imagine that. What could have possibly changed in America since the 1950s?