Monthly Antenna Sampler
A few years back Google launched a monthly sampler they were calling Antenna. The idea was to offer free tracks from both “essential” as well as “up-and-coming” artists.
It was nice for a while but slowly faded into an area of the Google Play Music section that was relegated to random odds and ends. They do still offer some free music tracks to listen to here but you’ll also find paid tracks, albums, duplicates, and other oddities.