We don't have that. We have functionally unlimited times now. Publishing something new today puts you at risk of litigation from existing rights-holders.
I don't believe it's morally right to license music but, if I did, I'd look at the climate of lawsuits in the the last 10-15 years and conclude that the risks might outweigh the potential rewards.
I'm all in favor of reverting copyright terms to what they were before the Walt Disney Corporation was founded, but I think the idea of having a limited time to profit off of your creative works in order to incentivize their creation is still a sound concept.
The original agreement was fair to both creators and society and would never be remotely palatable to today's industry of middle-men and rights hoarders.
I wish we could have it back. I would feel a lot better about "intellectual property", morally, if we did.