New York ? Whittle it down, and the essence of Howard Stern comes to this: a guy playing the piano with his … manhood.

One of Stern’s guests pulled that stunt during a Christmas radio show in 1987, and the bit – which was only heard, not seen – resulted in Stern’s first FCC fine.

“To me, that goes to the basis of what I do, which is outrageous, fun, sort of anything-goes humor,” Stern said last week. “It’s not the idea that the guy played the piano with his penis. It was sitting there and talking to a guy who would come up to the radio studio and play the piano with his penis. That’s what’s so great about the show. We could spend an hour with that a—.”

It’s been a long time since Stern could talk about a guy with that kind of raw musical talent on the air – he’s been saddled with itchy-fingered censors afraid of stiff FCC fines.

But this Friday marks Stern’s last show for Infinity Broadcasting, which carries his show around the country. Come Jan. 9, 2006, Stern moves to Sirius Satellite Radio. Off goes the censor.

“You get the old Howard back,” Stern said, sitting in his still-under-construction new studio. “For those who are aficionados of the show, they would say, ‘Howard, you stopped doing a lot of things you used to do.’ And they’re right. My personal standards have been reduced. … You get the same guy who comes on the radio and flashes you – he opens up his brain and lets you hear everything, the ugly stuff too, the horrible stuff, the real stuff, but you’ll get that now in a way that I haven’t been able to provide since 1987.

“I feel reborn, rejuvenated.”

Stern said he left over-the-air radio because escalating FCC fines forced everyone in broadcasting to pull out of edgy content. He no longer felt he could be creative.

“What happened was the total erosion of what it is that I do,” Stern said. “I used to wake up so excited. I’d plan out my show the night before, and I’d have four or five killer f— bits, but then I’d turn it off.”

Janet Jackson’s nipple slip at the 2004 Super Bowl didn’t help. Soon afterward, Stern was told he couldn’t air tapes of past shows – even shows that didn’t generate any complaints – because management worried they would lead to new fines.

“I’m amazed I’m still No. 1,” Stern said. “Between the edits, the commercials, the … ridiculous way I have to do the censorship on myself. I literally take hunks out of my act.”

But there is no censorship on satellite radio. And Stern plans to revisit some old material.

“What I’m going to do is go back and find everything I’ve been fined for and to make sure to do it in the first week. It will be phenomenal. You’ll see it will be so lame, you’ll see, you’ll go, ‘Who cares, who the f– cares. It’s so ridiculous with everything going on in the world.”

Stern’s team also has reached out to all the people he’s teased over the years – Rosie O’Donnell and Kathie Lee Gifford among them – to come on and talk. (So far, they’ve said no.)

And along the way, he’s squirreled away bits to use when he’s free to say anything.

“I’ve been keeping a running list,” Stern’s producer, Gary Dell’Abate, said. “I jokingly say, ‘Our first day at Sirius is 74 days long.”‘