There is something coy, wistful, agnostic, ecumenical, self-effacing in her speech and comportment that makes me feel at ease when I switch on her show, which she has been hosting since 1979. Some of the episodes I enjoy the most have been with Michel Petrucciani, Rosemary Clooney, Mary Lou Williams, Chick Corea, John Lewis, George Shearing, Aaron Diehl.
If you want a better portrait of Marian McPartland than I can paint, read the chapter "The Key of D is Daffodil Yellow" in Whitney Balliett's book, "Alec Wilder and His Friends," which Ben Ratliff lent me this summer. It is a wonderful book about some wonderful jazz musicians and singers, one cabaret singer, and two radio comedians:
If you don't have time to find this book, which, I think, you can only buy on Amazon--unless you get lucky at a used book store or rummage sale--watch this video, in which Marian talks about her style, and plays a bit:
Marian McPartland Talks About Her Sound