Yes GitHub is impressive that way.
As for the Dead, there can't be any doubt they have the most recordings. I have 7000 songs on my iPhone (1/2 or more from there). Anyway a funny CS story:
My friend has a Flapping Fish with Siri (or Alexa) inside. I had him try "Play Truckin' by Grateful Dead". Well it came back with "Hear is a popular GD song" - and it wasn't Truckin'.
But (1) Truckin' is in some US registry on popular songs (like top 10) - so "popular" wasn't even matched.
More challenging: (2) there are about 35,000 copies of Truckin' on Archive.org. They played it almost every night for 30 years - and there are multiple recordings on the same night.
So even if it found Truckin', which version do you want?
This is why speech recognition has a long way to go! And this example is my scalability for Computer Science gold standard.
Cheers,
scott