If the songs were permitted to lapse into the public domain, a session musician (who hit it big) like Jimmy Page could release his OWN compilation of the different artists’ tracks he played on.
And I fail to see “what” is different about seeing that the Beatles continue to make money off of Beatlemusic (when 2 of them are dead) when works by Elvis, Sinatra, and Louis Armstrong are now public domain under English law (and are appearing on low priced compilations).
They didn’t raise a stink when the artists who INFLUENCED them went PD.

IMHO, copyright should at least be as long as the person’s lifetime (in other words, as long as you are alive you still own the copyright to your works.)
Beyond that, I don’t know. You’re not talking about benefiting the person that created it, but their ancestors (which has to be balanced with the benefit to society.)
If I had to put a number on it, I would say the person’s lifetime or 50 years (whichever is longer.) That would cover people that die young, but still allow people to retain the rights to their work while they were alive.
“If Europe passes the directive to extend the term, the vast majority of financial gains - which will come direct from consumers’ pockets - will go to the world’s four major record labels and a handful of very famous performers.”
Don’t most session musicians sign those rights over to the record company in return for their initial payment at the time of the recording anyway? Which would make this a “protect the fat cats” proposal.
The European Commission is backing an extension to 95 years from release.That's ridiculous.
The problem with excessively-long copyrights is that stuff with a very small niche audience may disappear entirely, due to media being too degraded by the time they are public domain and thus legally copyable.