Semi-related, the technology used in Shazam and other music ID services grew from companies that monitored radio stations to make sure they were playing all the

Semi-related, the technology used in Shazam and other music ID services grew from companies that monitored radio stations to make sure they were playing all the ads they'd been paid for. In the mid-2000s, I worked on a Shazam-like text message service that would ID songs on the radio for you, and send you an iTunes purchase link. You texted us the radio station you were listening to, and we sent that and the timestamp to a server run by a company with listening stations all over the US, and it told us what song it was hearing at that time. The company's main clients were advertisers checking up on radio stations, but the technology worked just as well for music. It was a pretty sweet little service for the time, but sadly we never launched. I was amused when I saw far more polished apps like Shazam doing essentially the same thing, years later.