He’s a tort investigator by day and a trumpet player by night. And now, Peter Nater, 46 – who has worked at the city’s Law Department for 15 years – is a Grammy Award-winner, too.

And, no, he’s not giving up his day job.

A Bronx native of Puerto Rican descent, Mr. Nater is part of the 13-member Spanish Harlem Orchestra, which on Sunday night snagged the Best Salsa Album award for “Across 110th Street.” While the Grammy ceremony was unfolding in Los Angeles, the father of two was playing in Puerto Rico on a weekend gig, but when he got a text message instructing him to call the bandleader, Oscar Hernandez, he was in for a thrill.

“It was wonderful,” he said. After getting the news, he flew home on the red eye – and headed straight to work.

“I did want to stay longer, but I had to save my vacation days,” Mr. Nater said. He plans to take his daughters, Ashley, 11, and Lindsey, 13, to Orlando later this year.

Mr. Nater, who said he has perfect pitch, began playing the trumpet at age 12.

“I had a friend who lived on my block,” he said. “I remember hearing him practice. I asked my mother if I could take lessons, and she was very supportive.”

At 14, Mr. Nater started playing professionally and touring with a group led by Larry Harlow.

Though he was an enthusiastic player, his early days were a little rough. The first time he showed up to play with the Harlow band, the nightclub owner didn’t believe the youngster was for real.” He didn’t want to let me in. He said, ‘Get out of here, kid.’ I had to beg him to look for Larry Harlow,” Mr. Nater said.

As a young performer, he balanced school with music – as his mother demanded – and graduated from the High School of Music & Art, Bronx Community College, and City College’s Larry Davis Center for the Performing Arts.

Now, it’s evidence and investigations that he balances with his love of music.

“It’s extremely different work, but I’ve been doing it for so long that I got used to it,” he said.

Besides playing with the Spanish Harlem Orchestra, Mr. Nater performs with Giants of Latin Jazz, a mambo group. He played last year at a birth day party for the singer Marc Anthony – who was a nominee this year for the Best Salsa Album award – and a dinner for Mayor Giuliani. He also has performed with the singer Cyndi Lauper and appears on her new DVD, “Live At Last.”

Lucky for his bosses, Mr. Nater doesn’t come to work groggy and sleep-deprived from all-night jam sessions.

“I can pick and choose what gigs I want to do,” he said. “If it’s too late, I say no.”

Mr. Nater isn’t alone as a musician who has to keep up a very different job. According to the leader of Jazz at Lincoln Center’s Afro-Latin Jazz Orchestra, Arturo O’Farrill, the music business has changed so much in the past 30 years that many professional musicians must work outside the industry.

“When I was growing up, New York had a thriving studio scene,” Mr. O’Far rill said. “There were a lot of nightclubs, more salsa clubs, and a lot more opportunities for instrumentalists to make a living.”

With jingles and film scores being produced on synthesizers and digital work stations, however, the work for live musicians has decreased.

“A lot of music is made by mixing and DJs,” the orchestra leader said. “A lot of clubs have closed.” Discussing music for television and film, he said: “A lot of is underscore – music that is recorded and used for different purposes.”

Not only are different day jobs common, they can sometimes be helpful.

“It makes people freer musicians,” Mr. O’Farrill said. “They don’t have to play music they hate in order to pay their bills.”

Mr. Nater’s success also testifies to the positive effect of early musical education, the executive director of Jazzmobile, Robin Bell-Stephen, said.

“Arts education is a integral part to the development of any human being,” she said. Jazzmobile, which provides music education at city schools, was founded by the recipient of a lifetime achievement award at this year’s Grammy Awards, Billy Taylor.

While Mr. Nater’s Grammy has probably improved the water-cooler conversation at the Law Department – where his title is principal administrative associate – he sounded modest and quiet about it last night. He’s received attention and congratulations from his colleagues, but he said he’s not leaving for more fabulous pastures anytime soon. He’s planning to keep his good groove going.

The Spanish Harlem Orchestra’s next New York gig is April 15 at Town Hall in Manhattan.