In the old days, Audiogalaxy was one of the early successful P2P mp3 sharing networks. This was 1998 to 2002. It was groundbreaking because it was, AFAIK, the first one which let you resume an interrupted download from peers other than the one you initiated the download with. The fingerprint used for that was the file's hash, I think, so the filename didn't matter thouth ID3 tags did. In a time where lots of people were still on slow dial-up connections, this was huge.

It had a lot of other convenient features (good, specialised search engine, community features, network effects meaning you could find obscure stuff), but the robust fingerprinting and resuming was the big one. I also seem to remember that it had a very odd interface, where you controlled the app through the browser (I'm hazy on the details.)

Of course it was all quite obviously designed to facilitate copyvios and Audiogalaxy was subsequently killed, sold, repurposed and now resold. I had no idea the brand still existed.