"There's nothing like feeling an orchestra," Scott says. "Listening at home on your stereo is one thing. But actually being in the room and feeling the music is life-altering. It was to me."
Scott was speaking on the phone from Jackson, Miss., where she's filming Get On Up, director Tate Taylor's James Brown biopic, in which she portrays the second wife of the funk progenitor, played by Chadwick Boseman.
Scott had another formative experience within the storied walls of the Academy. "I went to the Philadelphia High School for Girls, and they had a class trip to the Academy of Music to watch a rehearsal. I can't remember what it was a rehearsal for, but I remember seeing this beautiful woman step on stage, with a bright smile. It was Kathleen Battle, and it was the first time I knew that a black woman sang opera. I had no clue. And that just immensely inspired me."
For Nézet-Séguin, Scott is an ideal headliner. The ball is a important fund-raising event for the financially recovering orchestra, which exited bankruptcy in 2012. But he also sees it as a key element in his efforts to instill "proactive pride" among Philadelphians in the august ensemble.
"I would say she is very much the right choice for our city: She's a big star, but she is also someone we can identify with," says the 37-year-old French-Canadian, who has just closed a deal on an apartment on Rittenhouse Square.
The maestro was speaking backstage from the Metropolitan Opera House in New York, where he was conducting rehearsals for Dvorák's Rusalka with Renée Fleming, which opens Thursday.
Nézet-Séguin's first Academy Ball, in 2012, featured jazz singer Diana Krall. Last year, Wolverine song and dance man Hugh Jackman was the guest.
"It's hard to explain to people who aren't from Philadelphia, or maybe even to Philadelphians who've never been there," says Nézet-Séguin, "but there's a mixture of getting back to the idea of a grand night, and also having an increasingly modern feel.
"My goal is to blend the classical with the modern portion. The Philadelphia Orchestra is known for a big tradition, and we are very proud of it, but we have so many musicians who all year long play in other ensembles. They play world music, they play jazz music, they play sometimes in rock bands."
Nézet-Séguin is jazzed for Scott's performance - which will include Gershwin selections and her own songs - for another reason: He's a fan.
"Honestly, before I came to Philadelphia, I didn't really have time - or, how can I say? - availability in my mind. It's so full always of music I need to learn, to conduct for the first time, that my world was almost exclusively classical. About five or six years ago, I started to discover R&B singers. I went to Motown, and then I discovered the Philadelphia Sound. When I discovered the modern diva, Jill Scott stood out immediately. And when I learned she was from Philadelphia, I was very excited. So it's sort of a little dream come true for me now."
Scott, he says, presents "the whole package. The way she has her own words, the poetry. The sincerity of the person. She's always herself. This is a value that's very important to me as an artist, and as a human being. And I think that's also a symbol of Philadelphia. That's something that's struck me about the city: People are themselves, and they don't feel the need to act a certain way. They are."
The collaboration with Scott is of a piece with the orchestra's scheduled performance with jazz bassist Esperanza Spalding last October at Carnegie Hall. When that show was canceled due to a stagehands strike, the orchestra played a free pop-up concert at the Kimmel Center. "We are on the right path," Nézet-Séguin says. "But we need to be doing more of this."
Glasper will perform the song "Calls" with Scott and the orchestra Saturday. The jazzman's Black Radio, from which "Calls" is a single, was the surprise best R&B album Grammy winner last year.
Of Scott, whose forthcoming album of "lullabies for adults" he is producing, Glasper, 35, says: "She's so honest. You know, a lot of people are not honest when it comes to music. But with Jill, through her songs, you feel you know her. Then when you meet her, you're like: 'Yeah, this is what I thought she was going to be like.' It literally is that. She's so transparent."
Scott says it's "like a dream" to be playing with the Philadelphia Orchestra. "I believe in genre-jumping," says the 41-year-old singer-actress-poet. "It's healthy for music to continually expand itself and cross-breed, in a sense. . . . It's good for music, and it's good for our city. This is very, very good. I'm happy for this marriage."
Nézet-Séguin takes up the baton. "I want to expand my own world, which is what we should all be doing as artists," the conductor says. "Music with a capital M is all in the same family. . . . 'This is classical, this is jazz, this is world, this is soul, this is blues.' At the end of the day, it's all about sharing emotion. We should stop putting things in these little boxes and think of it as one whole."
Philadelphia Orchestra 157th Anniversary
Concert and Ball
7:30 p.m. Saturday at the Academy of Music,
240 S. Broad St.
Tickets: $200-$250. Information: 215-893-1999 or www.philorch.org.