It's easy to spot the splashier renovations to the Academy of Music from the past couple of decades - the meticulously restored ballroom, or the enormous crystal chandelier in the main auditorium that now closely resembles the original.

Less obvious is some of the work being done this summer on the building, which has been, since 1857, the city's prime gathering place with a sense of occasion. In the past few weeks, during the brief window of time when the Academy wasn't hosting a graduation, Broadway show, or opera, the last of its 1960s-era HVAC units was replaced.

It may not have been visible from street level, but the parapet atop the building along the Broad Street side has been sliding into disrepair. Last summer, when the low wall capping the façade was inspected as part of a routine requirement, it was found to have suffered water damage - a potential safety concern.

"There was no perceived imminent danger, but there was enough deterioration of the brick and a perceived slight lean to the parapet that a restoration of it was warranted," said Sam Olshin, principal of Atkin Olshin Schade Architects, which is overseeing the work. "It became obvious when we did some historical research that the top of the building had a cantilevered flag pole off the parapet in the late 19th century, and the weight of the flagpole plus water getting in caused the brick in the parapet to rotate."

And so masons have spent the past few weeks pulling it apart, replacing deteriorated bricks with about 200 newly molded ones, and repointing the 60-foot-long structure. The wall is stepped out in places, an open invitation to rain and melting ice, so a new copper flashing will help keep water out. While this introduces a conspicuous new material, the copper should dull to brown quickly.

Restoration was also completed on the brownstone tablet in the center of the parapet engraved with the legend:



No one calls the building that anymore - the American has dropped from usage. The brownstone has been damaged (and patched) over the years, and the flaking and cracking was once again repaired.

But it won't be restored to its original appearance. The relief insignia, in fact, is not original to the building. An 1865 photo in the collection of the Free Library of Philadelphia shows another design - no words, but a garland draped around an instrument, perhaps a lyre. It is not clear when or why the current brownstone tablet was installed.

With restored stone, the brick repaired and replaced, new copper flashing, and new historically appropriate mortar pointing, the parapet should have a 50-plus-year extended life, says Olshin.

Also this summer, new steps outside the Broad Street entrance are once again being installed. All the steps were replaced in 2013, but several of the brownstone-colored composite-concrete slabs were found to be defective, and cracks formed "almost immediately upon installation," says John Trosino, a senior project designer at Jacobs who has overseen several restoration projects at the Academy. Six newly made steps are being put in place.

The Philadelphia Orchestra, which owns the Academy, has been on a program more or less every summer since the mid-1990s to renovate the building, and does so now in consultation with the Kimmel Center, which manages it. And future projects are hardly in short supply.

Restoration of ceiling mural is one example. That would require erecting scaffolding for nearly the entire height of the main auditorium, and the job would have to be sandwiched in during a rare dark period in the hall.

The cupola on the roof is in need of scraping, priming, and painting.

The seats are good candidates for replacement, and, if ever certain operatic repertoire were desired, the orchestra pit would have to be enlarged to accommodate the larger instrumental forces.

A bit of charming, if obsolete, technology was removed from the building this summer: an old wood hoistway in the south alley once used to bring oversize sets in the backstage door. Shrinkage was causing the brick mortar joints above it to crack, said Olshin. "The wood was removed, with the approval of the Philadelphia Historical Commission, and all mortar joints were pointed so the crack is imperceptible, and the building again is watertight," he said.

The elements take their toll on the building, and last January they wreaked havoc on one of its great traditions, the Academy of Music Anniversary Concert and Ball. For the first time, it was canceled, a last-minute call on account of snow. Yet the "vast majority" of donations for the fund-raiser remained, and the concert and ball that wasn't ended up grossing about $2 million, said Matthew Loden, the orchestra's executive vice president for institutional advancement.

The orchestra declined to disclose either the exact percentage of donations that stayed with the ball, or the amount netted.

January may not be the most weather-friendly time of year for a ball, but the event will remain at that spot on the calendar - the next one is January 28, 2017 - and more projects await funding.

Nothing has been decided for next summer, Loden says, but several of the building's stewards point out that the Academy's substantial cornice is in need of attention. The ornamental outcropping near the top of the building on the Broad and Locust sides may look like stone, but it is actually metal treated with a faux finish, says Trosino. "It hasn't been altered or repaired in a really long time. It's probably something that needs to be done to maintain it and safeguard it," he says. The new finish would have to resemble the old, he said, so as to look like brownstone.

"It's a huge undertaking."

It tends to be that way with a building about to mark 160 years.