Android has had music identification since at least the Nexus 4. Maybe it was 'built in' to the assistant now, but it's been around forever.
All you have to do is hold up voice search to music.
All you have to do is hold up voice search to music.
It runs 24/7 aongside the "ok google" detection, and as soon as it detects a song, it'll show the name on the lockscreen. So normally, all you have to do is look at your phone to get the song name [0]. This is also done 100% locally, there's a offline database of 10k+ songs which is only ~50mb [1], and gets updated regularly.
[0] https://venturebeat.com/2017/10/19/how-googles-pixel-2-now-p...
[1] https://www.xda-developers.com/google-pixel-2-now-playing-so...