How does one go about selling, say, a SF musical sitcom to TV?

I'm in the (slow) process of writing a TV script. It's a SF variation of the rather obscure British musical comedy series "Rock Follies". It tells the story of a group of young women struggling to make it in the music business. My variation is that we have a weirdly diverse quartet (one is a robot, one an elf, the other two are human), trying to earn a living singing in a nightclub which is actually an asteroid in space. It's going to be a "traditional" sitcom (with a live audience) sporting a good deal of SFX and the most unusual songs. Now, do I need to write out a full script, or can I submit a detailed synopsis?