Parties are fun. Music videos are fun. Parties WITH music videos are double fun. Period.
Ready to DJ? Of course you are.
It's simple as pie:
Brilliant! Launch the "player" on your laptop and mirror the tab to your Chromecast.
Lovely! Turn on your TV, connect your laptop via HDMI, mirror and launch the player. Boom.
Very retro. Just hook up the necessary audio cables and everything should work.