True Concord Voices & Orchestra didn’t waste any time building on the euphoria from its acclaimed performance late last month of Bernstein’s Mass.

This weekend, the professional choir joins with 40 vocalists from the University of Arizona’s Arizona Choir and more than 50 instrumentalists, many of whom are moonlighting from the Tucson Symphony Orchestra, to perform Verdi’s ambitious Requiem.

“We do these big pieces and oftentimes there are two, three of them in a season. Sometimes they are spaced out a bit more and sometimes they are right next to each other,” True Concord founder/music director Eric Holtan said.

Timing, of course, can be everything. Holtan planned the back-to-back masterworks to capitalize on Tucson’s winter visitor population — folks from places like Chicago and Minnesota who are big consumers and champions of lush, giant choral works.

Verdi’s Requiem is the second collaboration between True Concord and Bruce Chamberlain’s Arizona Choir. The two groups joined forces in January 2017 for Mendelssohn’s “Elijah,” which featured Grammy-winning baritone Richard Paul Fink and Holtan at the podium.

For the Verdi, Chamberlain takes the podium to conduct his first-ever Verdi in a career that has spanned four decades.

“I have prepared it for others, but this is my first go at standing in front of everyone and making it happen,” said Chamberlain, who is retiring from the UA in June after 19 years of leading choral activities.

The Verdi and the Mendelssohn are arguably two of the largest works Holtan’s professional ensemble has performed. “Elijah” brought together 70 vocalists and an orchestra of about 50. The Verdi calls for a few more bodies: 72 vocalists and about 60 instrumentalists.

“The Verdi Requiem is a very special piece and it requires a rather substantial, sophisticated orchestra and a choir of substance,” said Chamberlain. “We could never mount this at the UA School of Music. It takes a very special situation to make it happen and I’m very happy the situation has presented itself.”

The orchestra will include four horns, eight trumpets and four bassoons, along with a full contingent of percussion and strings. The string section will include Chamberlain’s two children: violinist Ellen and cellist Rob, who play with the TSO.

“This is a massive orchestra,” Chamberlain said.

The Arizona Choir will have 40 vocalists, including UA graduate students and Chamberlain’s wife, Peggy, who also sings in her husband’s other choir, the TSO Chorus.

“My entire nuclear family ... will be on stage,” said Chamberlain — the second time he has conducted his family members in a major choral work since he conducted the TSO’s “Messiah!” in December. “This is a very special moment and opportunity for me.”

“The piece is just transcendent and to have the opportunity to be able to say these timeless texts in Verdi’s language, given our situation in the country at the moment, everybody needs to hear this,” Chamberlain added. “It’s very poignant and very powerful for all of us.”

Verdi’s piece focuses on sin and salvation through a 19th century lens. But Chamberlain said contemporary audiences can find meaning “in what it is to be on this planet and how you are going to get off, the end game.”

“It is very critical we find out what salvation is for us as human beings and for humanity, and that is the message that Verdi (expresses) through all of these texts.”

True Concord will perform the Verdi twice: at 7 p.m. Saturday, Feb. 24, in Green Valley, and 3 p.m. Sunday, Feb. 25, at Centennial Hall on the UA campus.

Contact reporter Cathalena E. Burch at cburch@tucson.com or 573-4642. On Twitter @Starburch