If a company can't make a decent profit from a recording in its first 20 years, it means one of two things -- either the recording is worthless (in which case it isn't going to make much in the next 30 years anyway) or it spent too much money making the recording.

These days, you can make decent recordings without needing lots of equipment, so there's no justification for having big record companies and therefore no need for the present excessively long copyright protection.

One generation. If they haven't made a profit by then, it simply shows they're lousy at their job. And we shouldn't be burdening the next generation with the mistake(s) of the previous one.

The companies ALREADY make this decision - they should just be legally held to it.

When they let the material go out of print, the copyright should expire. This is the point at which the company's analysts have already determined the product is no longer profitable.