The 21st century’s response to the mixtape, Turntable.fm brings music to our virtual social lives. Didn’t Myspace already do this? Well, no. At least not nearly as well as Turntable is poised to.

So what’s so great about Turntable? In an age in which our social proof is displayed in a virtual world, Turntable.fm provides a truly social outlet for sharing musical interests. Though not required, most users actively engage in the scene of the (usually themed) “room” they are in. Hate the song that’s playing? Hit the “Lame” button and if others agree with you, the song will be skipped. Love it? “Awesome” will set your avatar’s head bobbing and give points to the DJ.

I had a blast just bouncing around the rooms meeting new people, but the true value of Turntable.fm will be leveraged in our existing social connections. This is currently implemented by requiring that one of your Facebook friends is using Turntable before you can make an account. Though surely helpful in avoiding the problems of scale that plague pivoting startups, this requirement encourages an organic growth in user base. When you bring up the room list, friends’ Facebook profile photos show up indicating their presence. “Fan” them and Turntable will email you whenever they step up to DJ. What better way to judge someone’s musical tastes than to see what they play to the public, and how it’s received? A recent night showed a “Google NYC” room ostensibly filled with Googlers DJing for each other in the office.

Turntable.fm would do well to exploit the social and game mechanics they have integrated to increase the quality of the musical programming. Currently the only benefit of points seems to be new avatars, but I could see the point system extending throughout the experience. Imagine when high scoring DJs score spots in busier rooms and those who receive bad scores are kicked out of the DJ booth. The current system provides little consistency as an empty seat goes to the quickest clicker.

There is a distinct lack of diversity in the musical tastes on offer. Of the current top 15 rooms by population, one third are “indie” themed and another third focus on electronic music. Some songs (RJD2’s excellent Ghostwriter, for instance) play over and over. The musical diversity will surely increase as Turntable’s population does, but it will be essential that the company helps expose that diversity through the interface. As the number of rooms explodes, Turntable’s developers must deliver an effective interface for browsing the choices. With only 30 rooms holding 10 people or more about a month after launch, finding a good place to hang out is easy. How will we navigate when this number is in the thousands?

I expect Turntable to be one of the most successful startups of 2011. Find me there DJing as PastaMasta.