Pop vs. hip-hop: The baton continues to be passed between the two most popular primary genres in the Hot 100's top 10. For the first half of 2021, pop was on top, with a 41% share of all top 10s, as compared to 34% for hip-hop.
Hip-hop won a tight battle for all of 2020 (41% vs. 40%), after pop took 2019 (48% vs. 34%) and hip-hop led in both 2018 (59% vs. 24%, a relative landslide thanks in part to Drake's dominance that year) and 2017 (34% vs. 29%).
Artistic 'License': Helping pop's strong showing, Olivia Rodrigo's "Drivers License" led the Hot 100 for eight weeks in January-March. Still, it reigned with certain atypical characteristics for a No. 1 in the first half of the year. Its length is 3:57, almost a minute longer than the 2:58 average for a leader in that span, owed partly to its signature bridge. Plus, its beats-per-minute is 72, below the average of 87 BPM for a No. 1 in that span.
The song also takes noticeably longer before its first chorus (53 seconds) than the average No. 1 (33 seconds) in the first half of 2021.
R&B on the rise: As a primary genre, R&B rebounded in the first half of 2021, claiming a 17% share of all Hot 100 top 10s (third-best, after pop and hip-hop). It scores its most prominent status since accounting for 20% of all top 10s in 2016, after which it declined to 15% for 2017, 11% for 2018, 10% for 2019 and 8% for 2020.
Silk Sonic most recently represented R&B as a primary genre atop the Hot 100 with "Leave the Door Open," for two weeks in April and May.
Electropop in decline: As a sub-genre, electropop/synthpop has retreated sharply in the Hot 100's top tier, from helping shape 40% of all top 10s in 2017 to 33% in 2018, 21% in 2019 and 11% in 2020. It climbed a notch to 12% in the first half of 2021.
Still, the sound is heard in two songs that topped the Hot 100 in the first half of this year: The Weeknd and Ariana Grande's "Save Your Tears" and BTS' "Butter."
'I know we weren't perfect, but …': A "love/relationships" lyrical theme, as in "Drivers License," remains the most popular for a Hot 100 top 10, appearing in 59% of all such hits in the first half of 2021. It repeats its reigns for all of 2020 (49%) and 2019 (66%).
Plus, and perhaps unsurprisingly, given months of social distancing, an "introspection" lyrical theme rose from 21% for 2020 to 27% in the first half of 2021. It was, however, already steadily advancing, from 16% for 2019, while it triples its share from 9% in 2017.