True commemorations of the Holocaust are, by definition, borderline unbearable: Its atrocities loom larger in history as time goes on.

Musically, Leonard Bernstein's Kaddish Symphony achieves much poetic truth, as narrated by Holocaust survivor Samuel Pisar. But Stephen Paulus' To Be Certain of the Dawn goes further with greater dramatic specificity, in ways that are simultaneously epic and intimate. It was performed over the weekend by massed choral forces and Chamber Orchestra of Philadelphia under the sure direction of Jeffrey Brillhart.

While many commemorative pieces reflect what the composer was induced (rather than compelled) to write, To Be Certain of the Dawn shows Paulus at his most genuine, while giving the subject matter its due: The huge forces (including Bryn Mawr Presbyterian sanctuary choir and children's chorus, the cathedral basilica choir, and archdiocesan children's choir, plus singers from area synogogues) rarely come together with collective bombast, but are parceled out in ways that allow the piece's dramatically varied series of episodes, each depicting the escalating anti-Semitism in Nazi Germany, to be fully realized.

The brilliance of Michael Dennis Browne's libretto is how that escalation is revealed in incremental, everyday terms - kids chatting in ways that reveal what's going on around them, juxtaposed against choral whispers about what Jews are no longer allowed to do (own animals, ride bicycles, etc.).

Some Holocaust-inspired pieces come out sounding like a horror movie. Paulus' does not. In a predominantly tonal idiom, he lets the incidents, characters, and Browne's words speak with their own power. The piece has some operatic thrust - most of it is through-composed, so it's constantly moving forward - though it's not tied down to a single, linear plot, maintaining the freedom to switch channels and have timeouts for variations on prayer. The piece never asks where God was in the Holocaust, reminding us that the tragedy was man-made, with God allowing what was then called "inner immigration."

The fact that the performance brought out all these qualities speaks well for it. Though the diffuse acoustic of the Cathedral Basilica of Saints Peter and Paul on Friday (Sunday was at Bryn Mawr Presbyterian Church) wasn't good for detail, it had ambience and overall musical force. Soloists (including Elizabeth Weigle, Suzanne DuPlantis, Randall Scarlata) were equipped to give the music whatever it needed, though tenor Michael Hogue delivered extra warmth and passion.