Clockwise from upper left: David Walker, Paul Max Tipton, Teresa Wakim, Lawrence Jones, Mary Gerbi and Sumner Thompson.

Mary Gerbi has assembled a powerhouse ensemble of early-music specialists from the Midwest and Northeast to come to Tucson — in July — to sing music that goes back nearly 500 years.

Yes, the Cambridge, Mass.-based mezzo-soprano has a bit of a wicked streak about her. When her colleagues arrive in Tucson this weekend to perform St. Andrew’s Bach Society’s “Monteverdi on the Edge” on Sunday, July 8, the mercury will top 100 degrees.

“I have been to Tucson twice in the summertime and I think it was 112 degrees,” said Gerbi, who is a regular with True Concord Voices & Orchestra and performed with the Bach Society last summer. “I have been to Tucson at least 15 times overall and I really think of it as a second home now. So it’s really fun for me to bring together my mostly Northeastern friends to Tucson.”

Gerbi will join soprano Teresa Wakim, tenor Lawrence Jones, baritone Sumner Thompson, bass-baritone Paul Max Tipton and David Walker on theorbo to perform music from his Monteverdi’s sixth and seventh books of madrigals, which bridge the gap between Monteverdi’s Renaissance era and the Baroque era of Vivaldi and Bach.

Gerbi curated the program and recruited the vocalists at the request of St. Andrew’s Bach Society Artistic Director Ben Nisbet.

“This is kind of her world and she and I had discussed this idea more than a year ago about putting together a concert like this,” Nisbet said.

At last summer’s Bach Society concert, Gerbi and Nisbet talked about this summer’s series — the group’s 30th — and Gerbi suggested early music composed centuries before Mozart, Bach and Beethoven. She is a regular on the early-music circuit, performing with chamber groups, in festivals and with orchestras around the country.

Gerbi admitted that some audiences might be unfamiliar with Monteverdi and other composers.

“Most people will be able to pick up on the fact that it’s very passionate,” she said. “Monteverdi ... was using texts that inspired him and then expressing the sentiments in those texts through music. So most of (his compositions) have to do with love or loss.”

Nisbet, who is in his seventh season as head of the Bach Society, has been programming vocal music for the past couple summer series to build on the area’s enthusiasm for the genre. Nisbet said much of that enthusiasm has sprung out of the success of True Concord, Tucson’s Grammy-nominated professional choir; the choral program at the University of Arizona Fred Fox School of Music; and the annual Tucson Desert Song Festival.

“When you are trying to program a concert series that is exclusively classical music ... you can’t just do instrumental music, especially when you consider just how much good vocal music and talent there is,” Nisbet said.

Gerbi said she has performed in various iterations with members of Sunday’s group, which Nisbet called a “powerhouse ensemble of early music specialists.” But this is the first time she will share the stage with all six.

“I’ve been telling my colleagues, ‘You are going to enjoy this so much’,” she said, describing the large, enthusiastic audience she experienced at last summer’s concert. “It makes it more fun for us to perform for people who are so excited.”

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