Incompetech, the website that hosts the music of Kevin Macleod, is a great place to obtain royalty free, quality music (attribution required). The music is cinematic and is designed to accompany film.
The music is free to use and for 20 euros you can purchase an extended license which provides you with:
- You don’t have to name the author in future projects you create
- You’ll get an official document as proof
- You can download the song as a wave file
- For many songs you get additional files
Check the Incompetech website for their terms as I have only highlighted the main ones here.
You can visit the original Incompetech website or the Incompetech section of the filmmusic.io website.
In regards to YouTube specifically, note the following that they have listed on their website (but as always check their website to see if they’ve changed anything since I made this post):
All in all, Incompetech is a great resource for cinematic music for filmmakers, but the music may not be subtle enough for things like podcasts or the background track of a YouTube video.