I've got a fairly good "ear" and given enough time can figure out a lot of guitar chords and notes just from mimicking what's being played on a source like an MP3. But then there are other times when I just can't figure it out. I bet there are a lot of players like me.

So then it comes down to finding either tabs or sheet music. Most of the time tabs from places like "Chordie" will suffice. But what if you like to learn music that never really made the hit lists? You have to dig for the sheet music somewhere. I'm not having much luck with doing that on-line for finding the pieces I'm looking for.

Question: When music is copyrighted and published, don't "they" create a piece of sheet music to establish their copyright claim? Can musicians find the original copyrighted piece of music by looking it up somewhere? Is there a sure-fire resource for finding all sheet music that has been published?