On: Old songs now represent 70 percent of the U.S. mus...

[kbelder]

There's more good old songs. That's because history is longer than present.

The total catalog of good music continues to grow; decades from now, an even higher percentage of good music will be old.

[bourgoin → kbelder]

That logic assumes that the amount of music produced is constant over time, which it isn't necessarily. The population grows and the barrier to entry keeps getting lower.