Our discovery led us to find albums containing tracks of multiple genres, and for the analytics we were then pursuing, we wanted to clean the data set and assign a single genre per album. We did that in SQL of course, and didn’t actually edit the data.
Finding the most frequent input value in a group is a job for the
mode() WITHIN GROUP (ORDER BY sort_expression) Ordered-Set Aggregate Function, as
documented in the PostgreSQL page about Aggregate