I was the author of MP3 Fiend around this time.
It was a desktop metasearch engine for MP3s that worked in conjunction with multiple download clients.
It was very successful at the time, only for Napster to come along and eat my lunch.
It got ... called out a lot by the press.
LOL, I know exactly what song you mean, but it was called I Want You. We did it in my a cappella group in 1997.
I ran my company's (unofficial) MP3 server in '99, and I spent a LOT of time managing files.
I ultimately went back to college in 2002 which was the right time to catch Apple's first attempt at Home Sharing in iTunes (I forget what it was called), where basically every single Mac on the campus network was running an HTTP server advertising all of its music for download.
Scour was released in November 1997, and it was released to solve the problem of a whole bunch of college students having their MP3 libraries available via Windows shares, but it was hard to find what you were looking for. Scour fixed that.
So maybe not the general public, but in 1997 someone released a search engine specific to finding MP3s, because people already had large collections.