St. Andrew's Bach Society is used to daring musical explorations that throw caution to the wind.

But even by the group's definition of ambitious, Sunday's concert ranks as one of the group's most daring.

For the first time in the classical music organization's 25-year history, it will perform an opera.

"It was something that we had never done before, and this is a perfect piece to do it on," Bach Society Artistic Director Benjamin Nisbet said about performing the concert version of Henry Purcell's Baroque opera "Dido and Aeneas." "When it comes to opera, it all comes back to great tunes and famous songs. This opera certainly has no shortage of those. 'Dido's Lament' is one of the most popular arias in the history of opera."

"This is an opera for haters of opera. It's in English, it's short - an hour long - and it covers the range of emotions," added Eric Holtan, who will conduct the St. Andrew's Bach Society Chamber Orchestra and a dozen of his professional singers from the Tucson Chamber Artists choir.

Sunday's concert is the first collaboration between Holtan's TCA and the Bach Society since they joined forces in 2007 for a concert of works by Britten, Bach and Brahms.

TCA's newly named principal mezzo-soprano, Theo Lobo, who is based in Boston, sings the role of Dido. Former Tucson soprano Kathryn Mueller, who is now based out of North Carolina, sings the role of Belinda.

"The singers and soloists we have coming in to Tucson to sing these roles are just so unbelievable," Nisbet said. "They have sung in Tucson and all over the world, and they are coming back to perform music that is right in their wheelhouse."

Purcell penned "Dido and Aeneas" in 1689 - one of the earliest English operas. It weds classical English sensibilities of the day with a fascination for the supernatural in a tale about the doomed love between Dido, Queen of Carthage, and the Trojan hero Aeneas. Purcell based it on the sixth book of Virgil's epic Latin poem "The Aeneid," which was written between 29 and 19 B.C.

The opera opens with Dido entertaining Trojan Prince Aeneas, who found himself shipwrecked on his way to Italy. Dido and Aeneas are in love, but witches and other mystical forces - among them a sorceress capable of throwing up wickedly destructive storms - stand in their way. The couple is separated when a Mercury wannabe tricks Aeneas into sailing off to Italy in search of his new Troy. When he leaves, Dido kills herself.

"This is baroque music at its finest," Holtan said. "Purcell was one of the great composers. Unfortunately he was bumped by Handel, who lived longer and wrote 'Messiah.' "

Sunday's concert closes out what Nisbet says is probably the Bach Society's most successful summer season. The group, marking its 25th year, hosted five concerts instead of the regular four-concert season.

"We've had consistently the biggest audiences. Last week (in a concert featuring oboist Lindabeth Binkley), we ran out of programs a half hour before the concert started. But I think artistically it's gone through the roof this year, which I think is the most important," he said.

How will the society top itself? Nisbet said he is working on next summer's season and has a couple of ambitious projects that he hopes will be ready by summer 2015.

If you go

• What: St. Andrew's Bach Society "Dido and Aeneas," featuring Tucson Chamber Artists.

• When: 2 p.m. Sunday.

• Where: Grace St. Paul's Episcopal Church, 2331 E. Adams St.

• Tickets: $12 adults, $5 students through

• Details: 808-2122.