There's so much free and nearly free music online these days (Spotify has a free ad-supported player, for example) that it hardly seems worth mentioning, but if you're a music lover, you shouldn't pass up the free tracks on tap at Amazon.
If you're a Prime subscriber, you get access to Amazon Music Prime, and that includes 2 million tracks (the more comprehensive Amazon Music Unlimited has 50 million tracks for an additional cost). But regardless of whether you are a Prime member, you can download and listen to thousands of free songs at Amazon Music.