Esperanza Spalding isn't being allowed to slip away from Philadelphia.

The four-time Grammy-winning jazz singer/bassist's custom-crafted Philadelphia Orchestra program to open the 2013 Carnegie Hall season was canceled because of a stagehands' strike. Not until now is she renewing that Philadelphia Orchestra relationship, with a concert Tuesday at the Kimmel Center that has her playing with the combined forces of the NYO2 youth orchestra and the Fab Philadelphians. Return visits are expected now that she's working with Opera Philadelphia as the librettist for a yet-to-be-titled stage work with music by jazz great Wayne Shorter.

The Tuesday concert with the Philadelphia Orchestra musicians playing side-by-side with musicians ages 14 to 17 is a huge unknown. A performer as ecstatic as Spalding will require the musicians to have the kind of spontaneity that's not often taught in conservatories. "Talk about being put in the hot seat," said conductor Giancarlo Guerrero, who has conducted NYO2 since its 2016 inception. "There are a lot of open-ended questions." Though the players are selected through national auditions and coached by some of the best professionals in the business, the arrangements have their complexities. They don't just put a symphonic frame around the jazz experience.

Rehearsals are few and take place not long before the concert. But the ebullient Spalding, now 32, has played symphonic pops concerts since the Carnegie cancellation. Happily, she speculated last week about what might unfold.

So much of your music feels so complete unto itself, I can’t imagine anything being added to it, much less a symphony orchestra.

As Wayne Shorter says, every project is a dialogue with the unknown. And he's right. But it's not like you're adding anything. It's like more branches have grown on the same tree.

Many of the branches in your music are loaded with hairpin turns and complex vocal harmonies. With limited rehearsal, how much genuine interaction is possible?

We come ready to make intricate music sound effortless. That's always the case. We can't help but interact because we're cocreating the propulsion of the music. Interaction is already written into the songs. It's not going to sound like we've been playing together for 30 years, but I'm guessing the students are prepared to respond to me, and I'm prepared to respond to them. There's a base level of professionalism … but it would be really nice to spend multiple nights with a large ensemble like this and work on all of the in-between stuff in rhythms and melodies. I've never had a chance to do that.

You tend to have a highly personal relationship with audiences. You do a lot of talking. You share information about your inner life. Your concerts make me feel like we’re best friends. But how possible is that to achieve on Tuesday, when you’re just one component of the program?

I think it's obvious that we're in this thing together. … Sound is moving through the audience. It's moving through all of our bodies at the same time. The vibration comes out of my mouth, through the PA system and physically enters their bodies. … I know maybe they haven't spent decades studying this music and how we phrase and communicate with each other. But I've made a frame so the audience can feel like they're part of the conversation.

My guess is that the orchestral world is not so alien to you, considering how you grew up in Portland, Ore., playing a lot of chamber music.

In high school, I was a classical bass major, and we all played in the orchestra. Much of what you practice is orchestral excerpts as well as soloistic pieces. So, yeah, it does feel very familiar. In the last 10 or 15 years, it hasn't been as familiar. It's a format I'm comfortable with and a culture that I understand — somewhat.

Tell me about your work with Opera Philadelphia.

They're so hip, so forward-looking, just to hang with [president] David Devan and [new works administrator] Sarah Williams. The conversation was delightful and really expanded my psyche with the whole experience. This isn't officially announced, but we're targeting the fall of 2019. I'll be in Philadelphia for about a week this fall [for the 017 Festival]. I'm studying so much opera and how the voice works when it's communicating dialogue. We have enough time to really find a way to make our own way of using the voice, and to make that fit in the format of what people have done before. We get to work with ensembles and vocalists and will have time to try things out. If they don't work, we'll adjust.

Why did you chose the Euripides-based subject matter of Iphigenia in Aulis? That’s where the warrior Agamemnon sacrifices his daughter Iphigenia as an offering to the gods amid the Trojan War.

The reason the story is so compelling is because it feels so relevant to the challenges that we face now. How do we come up with new solutions in which human life isn't sacrificed for the sake of victory or a goal? These characters died thousands of years ago, if they ever really existed. And they're told there's only one option. But nobody listened to Iphigenia. She's the passive protagonist of the story. But this time, she's not passive. The deadline is the end of August. But I'm sure it'll change many times between the first delivery and opening night.


Esperanza Spalding

7:30 p.m. Tuesday, Kimmel Center 300 S. Broad St., free, RSVP at