In order for your music to be eligible for the YouTube Content ID system, it has to meet several criteria. These include:
You must have exclusive rights to your music, so cover songs, tracks that fall into the public domain or are available through an open license (such as Creative Commons) cannot be submitted.
Distinct reference content
Your music must stand on its own in a meaningful way, meaning that things like karaoke tracks, production loops and sound effects cannot be submitted.
A single distinct piece
The music you submit must be a singular piece, so items like continuous DJ mixes, mashups or entire compilations submitted as a single track will not meet the criteria.
A few additional points to know when submitting tracks for YouTube’s Content ID system:
Guidelines for original video game soundtrack content
Tracks created for use in video games must be submitted by the publisher in order to be entered into the YouTube Content ID system.
Content that is sold/licensed on a commercial scale
Tracks that are part of royalty-free music libraries cannot be submitted for consideration.
You can view a comprehensive list of the criteria here.