When Larry Rosen celebrated his 60th birthday recently at this second home on exclusive Fisher Island, Fla., his mother took the mic and said how proud she was of her son, who had launched a successful career in recording and multimedia.

Then she cracked up the several score guests by expressing her awe over her sons most visible sign of success at that particular moment: The Count Basie Orchestra was the party's entertainment.

Mr. Rosen has combined his twin passions, music and technology, to become rich. He co-founded GRP Records, recording some of the first compact discs, and he later catapulted N2K Inc. to prominence as an on-line music site. That turned him into one of the earliest pioneers in Silicon Alley.

On the prowl

Today, Mr. Rosen, who lives in New Jersey, is restlessly exploring new technology. He consults with and invests in companies and sits on corporate boards. That's quite a career for someone who started out as a drummer.

He became a successful record producer after teaming with music industry legend Dave Grusin to form GRP in 1976. "I was concerned about one thing: the best possible sound quality," Mr. Rosen says. "It's not that we were smarter about where the world would go."

He and Mr. Grusin sold GRP in 1990 for $40 million, but Mr. Rosen's vision didn't dim. He grasped the Internet's potential for scraping inefficient layers from music distribution and forging close links with customers.

He became chief executive of N2K in 1996, establishing it as a leading stop on the internet for computer-savvy music shoppers.

N2K was one of the first digital companies in New York to make a public offering. It also made headlines with a series of bold moves, including hiring well-known producer Phil Ramone in an attempt to build the first online record label.

But N2K fell victim to competition from and in its main business, selling music over the Internet. Mr. Rosen eventually agreed to a merger with rival CDNow Inc. Then, needing a break from running companies, he stepped down.

Today, Mr. Rosen is a self-funded venture capitalist. One company he thinks has the future is FullAudio Inc., which promises to allow music lovers to download songs from the computer to stereos and eventually to portable devices.

Keeping busy

"He is not working full-time, but he is involved in so many projects that he is probably busier than he ever was," says Adam Zelinka, a vice president at Internet consulting firm Run Media Inc., who has worked with Mr. Rosen. "This is what he thrives on."

--Tom Fredrickson