On Thursday morning, Steven P. Jobs, Apple’s chief executive, showed off a new social network for music called Ping. It runs inside the newest version of Apple’s iTunes software. Ping also works on the latest software for iPhones and iPod Touches. (Apple hasn’t made it available for iPad this time around.)

It’s like “Facebook and Twitter meet iTunes,” Jobs says. “But it’s not Facebook, it’s not Twitter,” Jobs is quick to note — “it’s a social network all about music.” And guess what? It has 160 million users in 23 countries built in right away (Apple will presumably be opening it up to other iTunes users later). And it’s available on your iPhone and iPod touch — right in the iTunes Store.

Jobs notes that this feature is all about discovery. You can follow both artists and your friends. And you can be followed. With it, you get custom song and album charts to discover new music. And you can post your thoughts and opinions about your favorite music. Plus, there are 17,000 concert listing in the network.

Ping, Mr. Jobs said onstage at the announcement event in San Francisco, lets its users answer three burning questions: “What are my friends listening to? What are my favorite artists up to? What concerts are my friends going to?” And, he said, it resolves the driving need, “I’ve got to share this with my friends!” (It also answers the question: “Can I buy that song right now?”)

How does Ping work? Mr. Jobs describes it as “sort of like Facebook and Twitter meet iTunes. It’s a social network all about music.” Just as you may follow friends on Facebook, you can follow other Ping users. It may be the kid next door, or it may be Lady GaGa, who provided Jobs with a pre-recorded video clip for his stage show. Ping will let you know what music the people you follow are listening to, downloading, or just talking about.

Last.fm, MySpace Music, etc. — look out. Oh, and another Apple competitor has been doing something similar for a while — Microsoft with Zune. But again, 160 million users out of the box.

Ping is available as a part of iTunes 10 — which is available today.