Classical Fermi problem.
Make some educated guesses
Lets assume the average song is 5 minutes (not accounting statistical outliers like the live version of Free Bird). We'll use the closest order of magnitude so we'll call it 10 minutes.
While the Rolling stones are prolific produces and had around 300 songs, some artists were less so. So lets split the mean and say the average artist/group will put out 8 albums of 10 songs. So we'll say 100 songs. (closest magnitude! and pul the numbers out of wherever you want)
How many artists are there? And who do we count as an artist with a recording? Because I've got a hilarious little diddy some friends and I made about a certain bodily function spurred on by too much coffee. we'll say there's. We'll stick to actual music houses and assume they sign on 1,000 artists per year.
Aaaannnd I would assume that it gets pretty difficult to find recordings beyond a 100 years ago. So that comes out to 10^8 minutes or 190 years. This result boggles at first, and we might argue that in 1915 there weren't 1,000 active artists getting recorded. However today, it's quite easy for fools such as my friends and I to record "The Coffee Pot Runs", or local bands to upload their productions to youtube or soundcloud. Furthermore when you realize that youtube has more than 300 hours of video uploaded to it every minute, this result starts to make some sense.
The point being made that recording media is so cheap now that everyone can participate with such low entry costs that music is more than likely being produced all over the world at a rate far faster than any individual (or even coordinated group of individuals) could ever listen to in their lifetime even listening to more than one track at a time.
Roses are red
Violets are blue
Take the third hit
Then youuu....