I want to format a phone conversation - but I don't want to put it all. Ex. the first 10 seconds of the conversation, then I skip 30 sec. and put another 10 seconds. How do I do it? Do I need to create a new scene each time ?

JENNIFER
Alex?

ALEX
How are you?

A few moments later

JENNIFER
Your song is very good by the way. You’re very talented..

ALEX
Thanks.

JENNIFER
I hope you’ll make me listen to more.

ALEX
Sure.

A few moments later.

Alex is sitting at the piano.

ALEX
Where do you leave?

Oh, I know this one. Me! Me!

Well, I sort of know this one...

It's one scene.

There's an example of this in the short film script GOD in the downloads section on John August's blog. I've also watched the actual film (a short on his THE NINES DVD).

At scene 28, bottom of page 10. He just writes something like "Margaret is on phone. various positions."

The film shows her and does these overlaps from one position to the other, showing the passage of time. Very cool. The content is done with a VO (which doesn't sound like what you want.

What you've got looks like it would work.
Saipanwriter
http://saipanwriter.blogspot.com