The YouTube Audio Library is mainly aimed at people who need royalty-free production music to use in videos. However, anyone with a YouTube account can access the library via YouTube Studio and download as many songs as they wish.
An independent freeform radio station in New Jersey—curates the content. Most of the free song downloads are from lesser-known artists, but occasionally you will see a famous name pop up. Regardless, it is a great way to discover new music.
Jamendo is a platform that allows unsigned independent artists to easily distribute their music to their fans. It currently has more than 240,000 royalty-free tracks from 40,000 artists.
The artists who have listed their music on this site want something in return for the free download, typically a postal address or an email address. The idea is for the bands to easily connect with people who like their music—perhaps to advertise an upcoming tour or highlight the launch of a new album.