Unlike a wedding band that might just not have the ability to play EDM or mimic the latest hit by Halsey or Justin Bieber, your wedding DJ should be able to play virtually any style of music. Of course, they need to have a legal copy of all music being played. No, it's not like they can call up Spotify or Youtube and play anything available online. They need to secure legal copies of music for playback through DJ record pools or other subscription-based services available only to professional DJs.