You would send it a DM via SMS (which Twitter supported at the time) containing a few lyrics, and it would do a Google search of "<your input> lyrics", parse the search results, and in theory return the artist and title to you via SMS.
It never worked very well, but I was proud of it!
That allows me to ask ChatGPT questions from anywhere on Earth via a handheld satellite communicator (inReach Mini 2). It's kind of nice to be able to ask ChatGPT things from the middle of death valley.
Primarily I used it to google the address of a place I wanted to go so I could enter that in my TomTom. Times have changed.
Nobody imagined that P2P messaging (requiring multiple presses of a numeric keypad to type one character) would become as popular as it did, so an information service was the best use I could imagine, especially given the growing availability of data through the nascent Web. (Teletext was also still a thing, and we had a separate project for scraping that...)
But guess what those of us with access to SMS (and the general public) ended up using it for?
Apparently this is what my gen will rocker rant about.