Firstly, we apologize if this happens to you. We can assure you that all our music is 100% copyright clear. Using our royalty-free music with a purchased license is 100% legal, and you are not doing anything wrong.
Classical music has a higher risk of being misidentified by YouTube software since the composition remains the same; only the masters (the actual interpretations or recordings) are different. A Mozart piece performed by Olive Musique can be misidentified as the same Mozart piece interpreted by a different artist on a recording that may belong to Sony, for example.
Unfortunately, false or mistaken copyright claims are a known issue with YouTube and music libraries. The most efficient response is to simply counter the claim with your PremiumBeat license. The claim will then be dropped. You can read more about making a counter notification here.
Please note that your PremiumBeat license does NOT allow you to upload your project to YouTube’s Content ID system. PremiumBeat retains ownership of the recording. Due to the nature of YouTube’s content recognition software, uploading PremiumBeat music to Content ID will cause mistaken copyright claims for other users and for your future projects, and constitutes a violation of our licensing terms.
If you have more questions about the YouTube claim process, please contact us.