To see some good art right now in Philadelphia, you might want to go to jail.

The huge Eastern State Penitentiary Historic Site is hosting an impressive soundwork called "Pandemonium," by Janet Cardiff and George Bures Miller. (Cardiff also has an audio piece on now at the Hirshhorn Museum in Washington.)

Eastern State consists of the remains of one of the oldest and most influential prisons in the country. It opened in 1829 as the first modern "penitentiary": prisoners, kept in absolutely silent solitary confinement, were supposed to find penitence thereby. The prison officially abandoned its reign of silence in 1913 and closed in 1971. Since 1994 it has been kept on show in a state of "stabilized ruin," and parts of it are now used to showcase commissioned contemporary art. The Cardiff-Miller project is the site's latest and largest commission.

The couple have taken an entire cellblock, 356 feet long, and turned it into a kind of giant music box. Each of 120 cells has had an electric clapper installed in it, placed to strike one of the objects left behind when the prison closed. One clapper hits a broken bedstead, another bangs a toilet bowl, others are made to crash against the remnants of cupboards. Cardiff and Miller have programmed their clappers to strike in a 15-minute loop of sound, with effects that range from the barely audible to the cacophonous. Sometimes there's a delicate tapping followed by an eerie silence, as though a prisoner were trying to signal a companion without attracting guards. At other times, the artists have programmed a sequence of beats that's loud and almost danceable, as though the ghosts of inmates past were back for a house party. There are echoes of tolling bells, of a funeral march and one moment of clamor that sounds like a riot in full swing.

It's as though Cardiff and Miller have given prisoners the voice denied to them by Eastern State.

Pandemonium is at Eastern State Penitentiary Historic Site in Philadelphia through Nov. 30. Call 215-236-3300 or visit www.easternstate.org.

-- Blake Gopnik