It’s New Music Tuesday, the traditional day of the week for new releases. Apple has offered a free track (or three) of the week for a while now, though they do a lot more TV shows and shorts. But they update pretty late in the day, sometimes not til the next day or close to it.
Whoever is running the music store at Amazon must know that: they send an email bright and early, letting me know what the bonus track is and what else is new for the week.
Competition is a good thing.