Here you will find calm music in different moods and genres: low-fi hip-hop, soft piano music, chill and lounge.
Licensing on demand.
This music is free to download and you can use it in your non-monetized videos.
Perhaps your video will receive an automatic Youtube claim. This is OK, it only limits the ability to monetize a particular video, without other restrictions or sanctions: your video is safe.
If you want to use the music in commercial/monetized videos and remove the claim, you will have to buy a license. After buying a license, you will get an archive with high-quality .wav and .mp3 audio files.
Moreover, some licensed tracks have several versions of different lengths, which provides more flexibility for editing.
If you do not want to pay for the license, you can still use this music in your non-monetized videos.
More information about licensing and usage can be found in the FAQ.