Shazam is the closest thing we have to witchcraft. I'm sure plenty of HNers will chime in with "well acktually..." type comments about how they could write it in their basement in a weekend, but to do what it does, as quickly as it does, on the ridiculously enormous library of music that it does is really something special.
I don't mean to take away from Shazam (because I too was amazed when I first used it) but the Pixel phones have Shazam-like ability built in which uses minimal battery and without internet... and it's constantly running any time music plays. Not really "magic" how it works but still pretty amazing that I can pull the phone out of my pocket any time I hear a song I like and immediately see the band/title.
For anyone else finding this as implausible as I was, apparently the Pixel has a local database of 17,300 tracks. Still pretty impressive though.
https://uk.pcmag.com/news/91606/googles-pixel-2-phones-recog...