In rare occasions people experience copyright claims on Youtube even though they have credited me perfectly. Be aware that a claim of that sort would never come from me. The reason for why that happens is usually that a person has illegally uploaded my music to music stores under their own name. This might cause confusion cause the copyright claim might actually display another track title than the one you have used.
Yes it is copyrighted but free to use under circumstances explained in the main page. If you credit me you can use it and even monetize your video but as I have produced the music I am the copyright holder and holding the intellectual propriety.