PHILADELPHIA -- Technically speaking, the Pittsburgh Symphony Orchestra performed at the Kimmel Center here Thursday night on its "Great Orchestras on Tour" series. But it couldn't help getting in on the fun surrounding the mammoth new pipe organ.

How could it not, with the glorious instrument -- all 32 tons and 6,938 pipes of it -- hanging tantalizingly above the stage of Verizon Hall? Plus, since the PSO doesn't really have a concert organ, it couldn't resist an offer to play a work from this lesser-heard repertoire, in this case Poulenc's Concerto for Organ and Timpani. Led by conductor Manfred Honeck, the PSO triumphed in this and in Tchaikovsky's Symphony No. 5.

		Listen to organ audio samples at Kimmel Center.

The Fred J. Cooper Memorial Organ, which cost $6.4 million and is now the largest active concert pipe organ in the nation, took nine years for builder Lynn Dobson and his firm to design and create. It has been the focus of a festival of concerts and recitals, with the PSO wrapping things up.

The impressive instrument is the latest entry in a remarkable recent renaissance for the American concert organ. In the mid-20th century, American halls started removing organs, with the premise being that when unused, the pipes were resonating chambers that harmed auditorium acoustics. "The organ began to be seen as an illegitimate child of the orchestra," said Dobson.

But Meyerson Symphony Center in Dallas, Severance Hall in Cleveland, Benaroya Hall in Seattle and Disney Concert Hall in Los Angeles are among the halls to bring back this king of instruments, and the response has been unexpectedly strong among the public. "We had 2,000 people here for the organ marathon," said Mervon Mehta, the Kimmel Center's vice president of programming. "Once people hear an organ of this size and weight, they are overwhelmed by it."

It's also visually awe-inspiring, its pipes hanging in a maple "picture frame" from the balconies behind the orchestra. "We wanted the organ to be its own entity, not be part of the architecture," said Dobson. An unintentional nod to the nearby Liberty Bell comes in its upper left corner, where the typically hidden "bell star" chimes are in plain view.

Lest one doubts that a pipe organ can be popular: When the console was rolled out for the Poulenc concerto, the audience spontaneously applauded. The organist hadn't even stepped onto the stage yet.

The PSO welcomed organist Jeffrey Brillhart to the stage for the Poulenc, with its own Timothy Adams ably manning the extensive timpani part. Honeck, fresh from his impressive recent debut at Heinz Hall, led from the podium with the same marvelous attention to detail. Honeck is clearly a major talent, and his rapport with the musicians continued to be high. He asked for and received some truly musical playing from the strings in a work that, frankly, doesn't have much substance and is covered up half the time by a sinewy and angular organ part. This level of commitment, not to mention a warm sound, from the musicians was a tribute to the respect they already have for him.

Brillhart also was more interested in being a part of the ensemble than lording over it. When not unleashing the instrument for a few choice chords or solos, he blended admirably. Dobson gets credit here, too, as his scaling design lent the pipes a warm and mellow timbre. The buzz has been that it is the perfect sound for the lush strings of the hall's main tenant, the Philadelphia Orchestra, but it certainly also complemented the PSO. Just to let us know what the organ sounds like when "fully operational," Brillhart returned for an improvisatory postlude performance that shook the hall at times.

The Tchaikovsky surely shook some souls instead. Even more so than in Heinz Hall, Honeck tapped into a marvelous interpretation, full of angst and emotion. The winds capitulated more this time, going with the quicker tempos of the reading. From the quiet opening "fate" motive to William Caballero's delicate, measured horn solo to the overall crafting of the finale, Honeck inspired dynamic contours into the work. At times it was still a little too much drama and not enough beauty of tone in the woodwinds for me, but that's just a matter of opinion. All a critic wants is to be able to focus on interpretation, with ensemble, tuning and timbre taken for granted.

With Honeck, we get that. The PSO string sound under him in the Tchaikovsky and in a brisk Mozart's Symphony No. 40 had a string-quartet-like cohesiveness. And it's not as if his interpretations aren't good; they are simply different, which actually is refreshing.

As for that troubled organ at Heinz Hall, which actually broke down at an earlier rehearsal of the Poulenc, the PSO says it is in the exploratory stages of replacing it. Funds are always an issue, of course, but it is heartening that the deficiency may be addressed. A top organ certainly has enhanced Verizon Hall.