Yannick Nézet-Séguin conducts the Philadelphia Orchestra.

(Photo: Jessica Griffin)

Leonard Bernstein's "Mass" is a shaggy dog of a piece -- a messy, controversial creation from a musical giant. Orchestras and classical stations will lean heavily on the ever-popular "West Side Story" and "Candide" while celebrating Bernstein's 100th birthday this year. But this new disc from the Philadelphia Orchestra also deserves attention.

Critics hated “Mass” when it premiered in 1971. Audiences puzzled over it: Is it an oratorio, a Broadway score or a theater piece? Is it even classical music? The score calls for a small army -- full orchestra, two separate choruses, kids choir, full cast of soloists, marching band, rock band and dance company. The music shifts between genres so abruptly it can give a listener whiplash.

It is also strongly rooted in the early 1970s. Vietnam, Vatican II, and even The Who playing “Tommy” at the Metropolitan Opera were current or recent events at the creation of the work and the lyrics and score reflect that period. Given its history, “Mass” has done something surprising: it has remained relevant into the 21st century. Something about this line feels especially appropriate in Colorado in 2018:

Amen!

Half of the people are stoned

and the other half are waiting for the next election.

This recording succeeds by sounding contemporary. Yannick Nezet-Seguin’s theatrical strengths bring the army of musicians together for a cohesive and meaningful performance. The rock and pop music sound naturally integrated with the classical elements. Social unrest comes in cycles, but Bernstein’s call for peace in unsettling times resonates as much today as it did at its premiere.