Philadelphia Orchestra’s elaborate ‘MASS’ production requires litany of musicians

Rehearsing for this weekend’s production of Leonard Bernstein’s “MASS,” conductor Yannick Nézet-Séguin had much more than the full Philadelphia Orchestra to wrangle.

“We have the acoustic guitar and the traps, there. OK? Good,” said Nézet-Séguin to a stage chock-full of musicians on the first day of rehearsal in the Kimmel Center. To his right was a rock outfit with a trap drum kit and electric guitars; to his left was the orchestra’s brass section; in front of him were 100 choral singers from Westminster Choir and Temple University.

Thirty children’s voices from the American Boychoir, a high school marching band, a Mummer string band, and 16 Broadway singers also will join in the production.

In all, 300 musicians will perform Bernstein’s “MASS,” composed to open the Kennedy Center for the Performing Arts in Washington, D.C., in 1971. The requiem was commissioned by Jacqueline Kennedy, in memory of her slain husband, President John F. Kennedy.

“MASS” is the final installment of a long series of requiems programmed by Nézet-Séguin over the last three seasons. Due to its size and complexity, “MASS” is rarely staged.

“We’re trying to put together a real theatrical event. It’s a narrative, theatrical experience,” said director Kevin Newbury. “You can do the ‘MASS’ as a concert version, with musicians sitting behind music stands, but I think it benefits from a real theatricality.”

The narrative is about a mass that breaks down. The characters on stage have lost faith in their own institutions. Written by a Jewish composer for America’s only Catholic president, “MASS” portrays a struggle to regain trust in both religion and government.

“It’s a crisis of faith about an entire community grappling with questions of religion and leadership – government leaders and religious leaders,” said Newbury, who directed ‘MASS’ seven years ago with the Baltimore Symphony. “It covers a lot of ground. [Bernstein] wanted to make this a big opus. I think it’s one of his most exciting pieces — maybe his masterpiece.”

Bernstein debuted “MASS” around the same time as other extravagant rock musicals dealing with religion, “Godspell” and “Jesus Christ Superstar.” He worked with Stephen Schwartz, who wrote “Godspell.”

This production is updated from 1971 – there will be no flowers in anybody’s hair – with staging that Newbury hopes will reflect more contemporary concerns regarding government and religion.

There are so many elements in this production that the orchestra itself is pushed off the stage. Half of the musicians will be below Nézet-Séguin’s feet in the orchestra pit — the first time the pit will be used since Verizon Hall opened 14 years ago.