Ann Hampton Callaway brings that sentimental feeling to the BSO's Holiday Spectacular

"I'm very sentimental," Ann Hampton Callaway says, "a total mush-bomb when it comes to the holidays."

That's one reason the singer/songwriter is an ideal choice as host for the Baltimore Symphony Orchestra's 2009 "Holiday Spectacular." Jack Everly, the BSO's principal pops conductor, lists a few more.

"She's fabulous," he says, "one of the most delightful persons I've ever worked with. Hers is one of the unique voices we have today, an incredible voice. Add to that her abilities as an entertainer and a composer, and you have a rather rare combination."

Callaway will headline the 10 performances of the annual extravaganza, which features more than 150 performers, among them the show-stopping, tap-dancing Santas from the Baltimore School for the Arts. Freshly added for this year's lineup will be bass-baritone Daniel Okulitch, who made waves this season in the title role of Mozart's "Don Giovanni" at the New York City Opera, and an excellent saxophone ensemble from this area, the Capitol Quartet.

The Chicago-born Callaway, 51, who received a Tony nomination for her performance in the 1999 Broadway musical "Swing!" and reached a mass audience with the theme song she wrote for the TV show "The Nanny," has music in her DNA.

Her father, the late John Callaway, was not just a multiple Emmy Award-winning journalist (he was a longtime fixture on the public TV show "Chicago Tonight"), but also a spirited advocate of American popular songs. Her mother, Shirley Callaway, is a singer and voice coach. And her sister, Liz Callaway, is an accomplished Broadway singer and actress who has starred in several Stephen Sondheim shows.

"I used to think of us as the Von Trapp Family of Chicago," Ann Callaway says. "There was always singing in our house. I think every household should have singing. It's the most powerful way to let out your feelings."

Callaway unleashes her feelings with remarkable expressive power, whether purring or belting out a song, and her formidable vocal resources are backed by a strong sense of style. When she's in a jazzy mood, she can break into scat singing with disarming naturalness - a trait she attributes to her father's influence.

"He did scat singing around the house all the time. I thought all fathers did that," she says with a laugh. "It's like tap dancing with your voice. Of course, no one will ever come close to Ella [Fitzgerald]."

Among Callaway's dozen or so albums is one called "To Ella With Love," a collection of standards. Callaway could someday put together an album saluting another artist who been a major source of inspiration. This one might be called "To Barbra With Love" and would feature songs that Callaway wrote for Streisand.

The first of those is "At the Same Time," which Callaway finished on Aug. 16, 1987, with Streisand, one of her early musical heroes, expressly in mind. "I knew it was her song," the composer says. It took several years, though, before Streisand knew it.

In 1995, Callaway got a call from the famed singer.

"I started hyperventilating," she says. "I had been imitating her for years in my act, and I remember thinking when she got on the phone that she sounded like me doing her. We had a wonderful talk. She wanted some rewriting of the bridge in the song, and whatever Streisand wants ..." Callaway doesn't need to finish the sentence.

A decade to the day after Callaway wrote "At the Same Time," Streisand recorded it. And in 1998, during her wedding to James Brolin, Streisand sang "I've Dreamed of You," with a melody by Rolf Lovland and lyrics she asked Callaway to write.

The Callaway/Streisand connection continued with the 2001 release of "Christmas Memories," which includes a tender account of Callaway's "Christmas Lullaby."

"She's so iconic," the songwriter says of Streisand. "I still feel in a state of shock whenever I talk to her."

"Christmas Lullaby" won't be on the program for the BSO's Holiday Spectacular, but another of Callaway's seasonal songs, "God Bless My Family," from her 2002 Christmas album, will be.

And Callaway will also compose a song at each performance. She has long spiced concerts with improvised songwriting, using the audience as impromptu lyricists.

Last year, when she was the headliner for 28 performances of the Indianapolis Symphony Orchestra's Yuletide Celebration (the prototype for the BSO's show), she invited people to help her create a song about Indianapolis.

"They shouted out all the usual things - Pacers, Colts and Monument Circle," she says. "I'll do the same thing here to write a new song about Baltimore. It's my chance to get to know Baltimore better."

The unpredictable nature of improv does carry certain risks. During a previous Baltimore visit, when she asked for city-related suggestions, she misheard Shot Tower as "Shop Tower" and went on a riff about retail. "Sometimes not knowing a place adds to the humor," she says.

On the " Rosie O'Donnell Show" a few years ago, the host challenged Callaway by choosing at random words that studio audience members had written down. Callaway obliging improvised an emphatic ditty that somehow managed to make lyrical sense (to a degree) out of: yoga, belly-flop, hippopotamus, Munchkin, nauseous, exasperating, poopy and frisky.

"You need a hippopotamus in your heart, you need a Munchkin in your soul," Callaway sang, accompanying herself on the piano. "You'll be feeling frisky doing the yoga song."

As unlikely as those makeshift lyrics might have been, things could certainly have been worse. Asked about the most difficult assignment she had ever faced during songwriting improv, Callaway has a ready response and another hearty laugh.

"Someone called out 'a colostomy bag and shoes to match.' That was a challenge," she says.

Callaway has had extraordinary success creating music for words of a more sophisticated nature. She is the only composer to collaborate with the legendary Cole Porter, albeit from beyond the grave - with permission from his estate, she set to music his unpublished lyric, "I Gaze In Your Eyes." She plans to do the same for a Noel Coward lyric lacking a tune.

One more effort in this field came to naught. "One of my best songs was set to a Robert Frost poem, but his estate refused permission to use it," Callaway says. "Yes, sometimes a diva has heartache."

But not this week, as she plunges into the Holiday Spectacular.

"She's a remarkably sincere person," Everly says, "so it was natural thing for us to open this show with her singing 'We Need a Little Christmas.' It's like an invitation to a party in her living room - on a very large scale, of course."

Callaway genuinely relishes the music of the season.

"It starts getting played so early and we hear so much of it that people don't even know they're hearing it," she says. "Our job in this show is to perform it with so much soul and life that people will feel as if they're hearing it for the first time."