Firstly, what is a television magazine that will include music videos?? Is it a TV show? A magazine?

Artists are all signed to record labels, who handle all copyright and publication rights. So contact Sony, BMG etc etc.

This will be a show pretty much like etv's 20-something. it will feature a current hit song during the show. What i primarily would like to know is how Channel O does it coz they show unlimited music from all over the world ... do they contact each and every artists' label or there is a body that governs these things on behalf of the different labels?

you speak to the record labels.. that's it..

Like we've been trying to tell you, there's no umbrella body. Contact each record company individually and start doing some research on the TV industry, otherwise I see tough times ahead for you.