'Tonight, we commune with the dead," declared the intermission lecturer, Philip Jones, a Babylonian specialist. Is that so different from many classical music concerts?

This occasion was different. It was called "Ancient Echoes," a special concert at the Penn Museum's Chinese Rotunda on Tuesday, surrounded by Tang Dynasty sculptures. Egyptian sarcophagi lay in the next room. The event was special, indeed. The rotunda is a 90-foot-high dome: Acoustic spaces this diffuse and reverberant are so tough on preexisting repertoire that two new pieces were written for the space.

Lembit Beecher's Limestone kept the sound vocabulary small, with four percussionists working with sandpaper and similarly non-booming but busy sounds, suggesting the chiseling that created the winged-lion sculptures nearby.

Cellist Christine Lamprea was central in the unconventional narrative: Tapping the strings with a small stick yielded spare, insinuating, Asian-accented melodies. More traditional bowing of the instrument yielded not notes but more abstract sound shapes. Both polarities mixed and morphed as the piece went on, creating an attractive overall shape.

More ambitious was Scott Ordway's Tonight We Tell the Secrets of the World for small string ensemble. The audience was assigned the role of whispering ancient texts. The seating area was divided into three color-coded sections. Attendees in each section were given their own start-and-stop whisper cues via projections on the wall. My section whispered, from a sheet found on our chairs, fragmented writings from an ancient Egyptian pyramid. Others had Sumerian creation myths dating back as far as 3200 B.C. and Persian writings from the 12th century.

The whole package was a marvel. The contemplative string writing - recalling the slow movement of the Górecki Symphony No. 3 - drifted between emotional neutrality and wistful melancholy, with ascending and descending scales evolving into textures that went both ways at once. The soulful vocal lines, sung by Alize Rozsnyai, made a late, narrative-enhancing entry.

And the whispered texts? A composer such as Kaija Saariaho of Finland uses computers to supply atmospheric whispering. The audience was just as effective. All three audience sections merged during ecstatic moments, though not for long. Most amorphous musical events evaporated as soon as they reached fruition, making their own kinds of poetic statements. Words that seem like remote, stylized platitudes on the page took on many dimensions when read. My texts were like symbolist poetry with fleeting visual images. Not even the pedantic intermission lectures could keep this piece from casting its spell.