I think it's not a matter of the field (engineer or musician), but rather a matter of personality. I know some people who really take pride in their accomplishments at work, as if the project they worked on is really part of what they were proud to achieve in their life as a whole. I also know other types of people for whom being an employee merely means being at the service of a project that isn't theirs, which will therefore never deliver any actual satisfaction. For this latter category the true way around is to find a way to live by monetizing their own ideas and projects, either by trying to create their own company, or by trying to monetize open-source stuff, etc