A blaring ambulance siren and a mellow-toned cello: They hardly make perfect harmony. But they're the main themes in the life of Nancy Donaruma, who is retiring from the New York Philharmonic to take on another job she loves - as a full-time paramedic. After 31 years in the top-tier orchestra, playing with conductors including Leonard Bernstein, Zubin Mehta and Lorin Maazel, the 59-year-old cellist will go from a hefty six-figure annual income to a "low five-figure" salary. That's the price she's willing to pay to fulfill her lifetime fascination with medicine. "I've always had an interest in how the human body works - and doesn't," she said. "And I do like taking care of people." Donaruma says her physical skill as a cellist - manual dexterity and quick, supple fingers - "is good for starting IVs and feeling pulses." Other overlapping qualities are the ability "to be very focused and do something in an immediate fashion - and not to make any mistakes." Donaruma has even practiced her medical skills at the Philharmonic. In one case, a string player fainted onstage during a concert; Donaruma helped get the man off the stage and assessed his vital signs while a doctor was called. She also helped another musician who fell while walking off the stage. She'll play her last official concert with America's oldest orchestra Sept. 1 under conductor John Williams. The divorced mother of two grown children will still be very busy. She'll keep playing in chamber music groups and solo recitals, performing favorite composers like Beethoven and Brahms. And she'll play for free for her paramedic friends at Alamo EMS, close to her home in upstate Poughkeepsie. She has one word for her new job: "Exciting." Playing with other musicians and being a paramedic both involve "a lot of teamwork and creativity," she says. "You have to be very creative in figuring out how to move a patient. You work with a partner, plus police and firefighters. Everyone has a job to do." For the past several years, she juggled Philharmonic duties with paramedic courses at Dutchess Community College, while working several EMT shifts a month. Once, as a student, she was watching a surgeon perform a hernia procedure, with music piped into the operating room - a Philharmonic recording. "So in my peepy little student voice, I said, 'Oh, I'm on that record.' And the surgeon said, 'What are you doing in here?'"