+1 and also the fact that Google Pixel's "Now Playing" feature is such an amazing application of the same idea. Though I wonder how different are their implementations
I also love that it just shows up on my lock screen.
Recently for whatever reason I was listening to the twist/ cover "Stacy's Dad" and Now Playing recognised it as the rather more famous original Fountain's of Wayne "Stacy's Mom". So yeah, it doesn't know everything. It also doesn't recognise lots of obscure stuff I own that's like B-sides or special editions that never saw radio play, or bands that my friends were in (but everybody I know has read both Steve Albini's "Some of your friends are probably already this fucked" and the KLF's "The Manual" and so none of them signed a recording contract and thus you've never heard of them) but I've never had a situation where I heard something I liked at like a bar or somewhere and Now Playing didn't know what it is.