But on these fronts, the Kimmel - now in its 10th season and hundreds of millions of dollars later - is still very much a work in progress.
The Kimmel has made progress on its finances and is now debt-free, and it has succeeded in deepening its relationships with resident companies.
But there is much to do. Renovations will make way for a restaurant expected to open in December in a more prominent site, on the ground floor where the gift shop was.
The rooftop garden, originally promised by architects as a habitable and climate-controlled space, is so hot or cold it's unusable much of the year. Soon, after millions more are spent, the space will be enclosed in a dome, in a stab at creating a rentable space for special events.
Acoustics are still undergoing improvements. Philadelphia Orchestra players on one side of Verizon Hall's stage say they can't hear what's being played on the other; this, plus studies by acousticians finding a lack of overall presence of sound in the audience, has compelled the Kimmel to undertake another round of corrective construction this summer.
"The minute the orchestra is off for the summer we go to work," said Anne Ewers, the Kimmel's president and chief executive officer.
The rooftop garden, acoustic projects, and new restaurant are being paid for with $7 million in philanthropy, plus $7 million from the state Redevelopment Assistance Capital Program (which provided tens of millions of dollars for initial construction a decade ago).
Bringing climate control to the rooftop garden will yield a substantial stream of rental income, the Kimmel hopes, for weddings, parties, and other events.
"We're getting a thousand inquiries a year - and we do 17," Ewers said.
Change is critical to the future, but the Kimmel already has overcome some enormous challenges.
After falling short in its initial $275 million fund-raising campaign, the center opened with debt payments that became a drag on the budget. A group of local foundations and philanthropists came to the rescue, and the Kimmel is debt-free.
A Kimmel-commissioned study has determined that the center has become a major contributor to the city's economy, Ewers said, though she declined to provide the study or even an executive summary.
Initial tensions between the Kimmel and some of its eight resident companies have eased - many say through dealings with the indefatigable and merry Ewers, who took over in 2007.
In fact, the Kimmel recently shifted its mission to be slightly less interested in its own presentations and more supportive of its resident companies. Some of its presenting mission has been outsourced to corporations such as Live Nation, which Ewers said had allowed the Kimmel to reduce rents for resident companies. Fees paid to the Kimmel by the Philadelphia Orchestra and other groups are being renegotiated.
And Ewers said the center was on the verge of a new relationship with the Philadelphia Chamber Music Society, the city's largest presenter of string quartets, vocal recitalists, and small-ensemble repertoire. Although PCMS has been an official resident company since the Kimmel opened in 2001, it cannot always afford the high rents of the 650-seat Perelman Theater, so it divides its season among a handful or more venues each season.
Starting in 2012-13, pending negotiation of a new rental agreement, the Kimmel and PCMS will copresent five to 10 Perelman concerts, effectively handing over the Kimmel's curatorial role to PCMS for certain kinds of artists.
"It's been our desire that there be more lit nights at the Perelman," said PCMS executive director Philip Maneval, "and to the extent we can help accomplish that I think it's to everyone's benefit." The Kimmel already coproduces with the Opera Company of Philadelphia and Curtis Institute of Music.
The Kimmel calls reduced rents to its resident companies a "subsidy," which Ewers quantifies at $6 million annually (up from $4.6 million).
U.S. arts centers vary in how much outside artistic "product" they import versus how many indigenous groups they present. At one end of the spectrum, the Woodruff Arts Center in Atlanta exists primarily to serve its resident companies. When the Kimmel Center opened, it aimed to be closer to the Lincoln Center model, bringing in music Philadelphians weren't hearing - world music, visiting orchestras, and a plethora of arts that don't easily fit into traditional categories.
But that mission shifted with the reorganization. It's a subtle but important change - and one that is increasingly blurring the line between art and commercial entertainment.
The Kimmel's new partnerships with the likes of AEG Live began to filter onto the Kimmel Center Presents roster in the fall with the appearance of stand-up comic Louis C.K., "Cake Boss" Buddy Valastro, and pop acts.
This spring, the Kimmel is putting much of its curatorial muscle into the three-week Philadelphia International Festival of the Arts, which will begin April 7. Though in many instances the festival umbrella covers artistic endeavors that were already scheduled, there's no question that the Kimmel has fostered partnerships among local arts groups and, as a conduit of $10 million from the Annenberg Foundation, boosted budgets for projects that would not otherwise have happened.
But a return of the festival is not guaranteed.
"We'd love to do it in 2013, but we'll have to see," Ewers said. The question, as always, is funding. Since the death of Leonore Annenberg, the foundation has largely shifted its focus away from Philadelphia.
The Kimmel as a solution to the Philadelphia Orchestra's decades-long, if intermittent, search for better acoustics continues to evolve. The aim of the summer acoustic work - designed by Threshold Acoustics of Chicago and estimated to cost $1.2 million - aims, in broad terms, to get more sound out into the hall and to allow players on stage to hear one another better. This latter quality is key to achieving appropriate balance between sections but even more so to allowing musicians to play together.
To achieve this, two towers will be constructed, one on each side of the stage. Modifications to the soffit and sections of the wall areas flanking the organ console at the Conductor's Circle aim to improve the hearing conditions for performers on stage as well as singers within the Conductor's Circle, said Ewers, and the towers should allow downstage strings to "hear optimally."
The overall change, Ewers said, will "really allow sound to blend and come further into the audience."
All of the Kimmel's activities - from its own presentations to supporting local troupes with lower rents - could be enhanced with a larger endowment.
But given the economy, now is not the time.
"The fund-raising climate is still a challenge," Ewers said.
Contact music critic Peter Dobrin at email@example.com or 215-854-5611. He blogs at www.philly.com/philly/blogs/artswatch