I'm impressed with my pixel's ability to do it. I forget it's on sometimes and I'll walk in a pub. Having only been inside 5 seconds and my phone in my pocket the whole time, it already has the song playing on display on the lock screen. Its almost like it works better when the volume is lower. I have a harder time detecting music with it if I turn the volume up or hold it near a speaker. Put it my pocket and have 30 people talk over it? Probably has a 95%+ successful detection rate in those conditions