Yesterday afternoon, Marian McPartland entered her hotel suite for the first time only to find an upright piano occupying much of what used to pass for a living room. It's not that the jazz pianist will be lacking an instrument during her week-long stay at Charlie's; it's just that she's become a popular guest with symphony orchestras and, with a Grieg concerto coming up soon, "I thought I needed to woodshed a little bit. I hope my neighbors won't be offended," she says worriedly. "Either they like what I play, they don't hear or they don't care because everything is so loud."

It's elegance, not loudness, that has made McPartland one of the most successful women in jazz today. The elegant lyricism of her uptown swing is symbolized by her New York base of operations for the last eight years, the luxurious and very "in" Carlyle, also home to Bobby Short. The genteel ambiance of the Carlyle and the appearances with symphonies came about, McPartland says, because "I was trying to think of a way to get me out of nightclubs, 'cause I can't stand the smoke and not being listened to."

Americans have been listening to the British-born pianist since she came over as the wife of traditional jazz legend Jimmy McPartland. Now divorced but still closest of friends and occasional partners, the two first met in Belgium in 1944 when their respective USO bands crossed paths in a GI's behind-the-lines tent jam. McPartland admits that her "sense of time wasn't good. I was overly enthusiastic, but I think he liked my harmony." For many years, she played in her husband's band, finally going out with her own trio in 1950.

First in Chicago, and later in New York, McPartland listened and learned, becoming increasingly assured in the process. "I was playing somewhat cornily when I came over here, and even then it took a while," she admits. "I was a late starter. Jimmy always swore I would never learn how to swing; if you didn't, you never would, that was it. But he had to change his mind," she says with a smile.

While her husband stuck to his Dixieland/traditional guns, McPartland was following the changes in jazz, cautiously experimenting in the footsteps of George Shearing and Lennie Tristano. She was also becoming involved in the history of women instrumentalists in jazz, a project that will eventually translate into a book for Oxford University Press. McPartland admits that she's overwhelmed with a wealth of material on the many unheralded or forgotten women in jazz: "It's a life's work. I've worked with a great many of them, but the ranks are thinning out," she says, referring to the recent deaths of Hazel Scott and Mary Lou Williams. "Luckily, there are some new ones coming up."

McPartland, who hosts and produces National Public Radio's weekly "Jazz Piano" series, also runs her own record company (Halcyon), records for another (Concord), and still finds the time for frequent teaching workshops (she just finished a residency at Interlochen in Michigan). "I'm afraid to take time off," she laughs. "I'm into so many good things right now." McPartland is a bit worried, though; writers keep calling her as a subject for chapters in their books about women in jazz. In fact, she may have to show the spunk and initiative that marked her entry into the symphony scene.

"I did a terrible thing," McPartland confides. "I called up the director of the Rochester Symphony and he asked me what I would play. I said the Grieg Concerto, he said 'fine.' I hadn't even learned it at that point. Luckily, the date was a year ahead, so I went back to studying." She pauses for a moment. "Horowitz certainly doesn't have to worry about me."