Keeping Secrets

Without doing the proper amount of research on this topic (I'm sure there are legitimate answers to this curiosity that I will find and share), I have wondered if there is any type of meaningful digital or symbolic information that couldn't eventually be copied and shared. I'm thinking of audio files, for example. Imagine someone creates or utilizes a current technology that ostensibly makes it impossible for a particular audio file to leave a person's computer. How would that actually be possible, at a fundamental level? Would there be some code that prevents the audio file's contents from moving locations in memory, assuming the contents are basically just a massive list of floating point values? This seems infeasible. Moreover, with music itself, why couldn't someone simply record the output of a given audio file and share that? Keeping information "a secret" seems to get really tricky when one gets into the details of it.

More on this later...