Google is testing a new YouTube feature that lets you hum or record a song to search for it.
If you’re part of the YouTube experiment for the feature, you can hum or record three or more seconds of a song so that Google can try to identify it, according to a support page. Once YouTube identifies the song, it will show you relevant content about that song. Basically, it’s a Google-y take on Shazam, which is owned by Apple.
That’s what I originally used it for years ago. I don’t know if that’s what it was intended for, but it worked well enough that I kept using it for a while.