spotify, believe it or not. for the genres of music that i nose around in it has an amazing catalog, i can listen all thru the house thanks to alexa, and i can favourite or skip a track with voice commands. i pay for the premium version because i hate ads and also because i want to listen to music at higher quality than 192kbps
shazam is one click away from being opened after i unlock my phone at any point. holy shit that's been a good resource when i'm out somewhere and hear something i like.
after that, however, i spend a lot of time on bandcamp hunting for obscure and decent sounding remixes of popular songs. THAT's what i dump on a dancefloor full of hippies. if you get the girls dancing then the boys dance with them and with charismatic music you can turn it into a party instead of just a bunch of people dancing to music
oh, and when you're listening to music that you're thinking about DJing with, you absolutely utterly NEED an enormous subwoofer and a surround sound hifi so you can hear it the way it's supposed to sound