At 8:20 Monday night, cars were still jamming into upper Massachusetts Avenue by the Washington Hebrew Congregation. Seven choral groups take up a lot of parking spaces, but no one seemed aggravated.

The initial focus of attention was a sole brown-robed figure, Shaik Fathy Mady, intoning the Moslem call to prayer. Since Mady's culture does not consider these rhythmic recitations to be music, the intricate piece was greeted by silence, not applause. A flurry of organizational activity followed. A rabbi gave a welcome, a minister read a mission statement, a hand-bell choir tolled. Streaming in through the aisles, hundreds of singers transformed the synagogue into a landscape of blue robes, dotted with a few orange turbans worn by the Sikhs. The 11th Annual Interfaith Concert had begun.

It is not only what these seven groups sang that was different, but also how they sang. The audience was frequently called upon to join in throughout the concert, making a kind of cross-cultural sing-in. The St. Mary of Sorrows Roman Catholic Church Choir was rather methodical about this, providing simple Latin refrains in the program book, which lured the audience into a proper place in the magnificent musical architecture. The Colesville United Methodist Church Gospel Choir had everyone swaying and clapping from bar one of the Kevin Yancy tune "Sign Me Up."

The power of an African-based call-and-response also has its counterpart in the Jewish liturgy. But the cantorial art is a 19th-century virtuosic tradition. Instead of making you want to sing, a voice like that of the Kol Rinah Choir's director, Washington Hebrew Congregation's cantor Mikhail Mannevich, takes your breath away.

On the other hand, nothing about the Sikhs' hymns calls attention to them -- reflecting the private, internal event of worship. Drums and drone instruments (sitar and harmonium) contributed to this lush, tightly woven musical fabric.