How Can I Play Music with the MacBook Lid Closed?

I'm looking for a way to keep my MacBook playing music even when I close the lid. I'm not referring to the automatic sleep mode that kicks in after a while, but rather when I intentionally close the lid. Since my phone is out of commission and I lost my MP3 player, my MacBook is my only option for listening to music during my public transport commute. I find it awkward to hold the Mac in an open position while I cradle it. I've seen that both iPads and iPhones allow music playback with the screen off, so I'm wondering if there's a terminal command or setting tweak to achieve the same on my Mac. Any help would be appreciated!