Falling leaves, falling temperatures and costume parties mark the end of October and Halloween.

Appropriately, three of this week’s top items from southern Maine’s arts and entertainment offerings relate to Halloween and horrors, at least tangentially.

An outstanding choice is “Vanya and Sonia and Masha and Spike,” the Tony Award-winning comedy that opens Good Theater’s 15th season and runs through Nov. 20. The pivotal event in the play is a costume party.

“Dr. Jekyll and Mr. Hyde” was one of the first horror movies made in Hollywood, and Friends of the Kotzschmar Organ plan to screen the classic 1920 silent film on Oct. 29, accompanied by their massive instrument.

The featured work on this Tuesday’s Portland Symphony Orchestra concert is an orchestral suite from Bela Bartok’s only opera, “Duke Bluebeard’s Castle.” The story revolves around a murderous nobleman from medieval times.

Expect no horrors when the Portland Conservatory of Music presents its fifth annual Early Music Festival Friday through Sunday.

‘Vanya and Sonia and Masha and Spike’

Sibling rivalry is an ancient theme in stagecraft, harking back to the Greek playwrights of the fifth century B.C.

Twenty-six centuries later sibling rivalry provides the dramatic horsepower behind “Vanya and Sonia and Masha and Spike,” a comedy by Christopher Durang that copped the 2013 Tony Award for Best Play. Portland’s Good Theater has opened its 15th season with a very funny and insightful professional production that runs through Nov. 20.

I am a longtime regular at Good Theater, and this show is definitely one of the company’s best efforts.

With multiple intentional nods to the ancient Greek authors as well as 19th- century Russian playwright Anton Chekhov, Durang has crafted an extremely intelligent and witty comedy that revolves around three middle-aged siblings – the first three names in the title – plus a trio of other characters orbiting their lives. The insecurities of middle age provide both comic and dramatic fodder for Durang.

The principal dramatic axis connects sisters Sonia and Masha, with standout performances given by Laura Houck as the former and Lisa Stathoplos in the latter role. Paul Haley, playing Vanya, has one of the biggest and best monologues ever staged.

I also loved the other three: Marshall Taylor Thurman as Masha’s handsome, muscular, feckless boy toy, Noelle LuSane as a wacky, soothsaying housekeeper and Meredith Lamothe in a curious sort of semi-ingenue role. Brian P. Allen shows a sure hand as director. The exquisitely detailed set, by Cheryl Dolan and John Sundling, adds immensely to this production.

Good Theater presents “Vanya and Sonia and Masha and Spike” at the St. Lawrence Arts Center, 76 Congress St. (top of Munjoy Hill) through Nov. 20 with 7 p.m. performances Wednesday and Thursday, 7:30 p.m. Friday, 3 p.m. and 7:30 p.m. Saturday and 2 p.m. Sunday. Call 885-5883.

Friends of the Kotzschmar Organ

Every year on the Saturday before Halloween, Friends of the Kotzschmar Organ presents a horror movie dating from the golden era of silent films, accompanied by the massive sonic machine that is the centerpiece of Merrill Auditorium in Portland City Hall.

This year’s film selection is “Dr. Jekyll and Mr. Hyde,” a 1920 adaptation of the classic Robert Louis Stevenson novelette. This year’s guest organist will be Jonathan Ortloff, who holds a degree in organ performance from the Eastman School of Music. Ortloff not only plays huge organs, he builds and repairs them.

By tradition, silent film accompanists improvise on the keyboard, matching the actions on screen and intensifying the mood and emotions of the characters. “Dr. Jekyll and Mr. Hyde,” which deals with a man with diametrically opposed personalities, provides plenty of material for Ortloff’s keyboard artistry.

Catch “Dr. Jekyll and Mr. Hyde” and the Kotzschmar Memorial Organ at 7:30 p.m. Oct. 29 at Merrill Auditorium at Portland City Hall. Call PortTix at 842-0800.

Portland Symphony Orchestra

Two very different works comprise the Portland Symphony Orchestra’s upcoming Tuesday Classical concert, which will be led by maestro Robert Moody and feature four guest artists.

The first piece will be Johann Sebastian Bach’s Concerto in D Minor for Two Violins and String Orchestra, a Baroque masterpiece that is characterized by the vastly increased opportunities for counterpoint afforded by two virtuosos.

Following intermission, Moody has selected excerpts from Bela Bartok’s only opera, “Duke Bluebeard’s Castle.” The story revolves around a murderous duke from medieval times who has dispatched his first three wives and is about to do away with the fourth. Her efforts to escape near-certain doom provide the story line of this ancient French folk tale.

Catch the Portland Symphony Orchestra at 7:30 p.m. Nov. 1 at Merrill Auditorium at Portland City Hall. Call PortTix at 842-0800.

Portland Early Music Festival

In decades past, Mainers who wanted to hear live performances of “early classical music” – a time-frame and genre centered on the Renaissance and Baroque periods – mostly had to travel out of state. Local artists were few in number and performance opportunities were quite limited.

That unfortunate situation has changed in recent years, and one of the driving forces behind the recent efflorescence is the annual Portland Early Music Festival, a production of the Portland Conservatory of Music that’s running this Friday through Sunday.

This year’s festival, the fifth, features four ensembles in three days in two locations. The Friday opener is the Berry Collective, a group that was formed by keyboard artist Sylvia Berry, a Philadelphia native who has performed extensively in the U.S. and abroad. Berry specializes in early keyboard instruments (harpsichord and fortepiano) as well as performance practices of the 18th and early 19th centuries. Friday’s concert will focus on piano quartets written by Wolfgang Amadeus Mozart.

On Saturday the El Dorado Ensemble holds forth. This Massachusetts sextet specializes in early string instruments, and the program will be Renaissance music from England and Spain.

Two Maine groups are slated for Sunday. First up is the Bowdoin Chamber Music Choir, led by music professor Robert Greenlee, performing English madrigals from the time of King Henry VIII. Next is St. Mary Schola, led by University of Southern Maine music prof Bruce Fithian. The Schola numbers about 20, combining vocalists and instrumentalists. They are Maine’s pre-eminent early music ensemble, and their Sunday program highlights excerpts from an opera by Italian Baroque master Claudio Monteverdi.

For more information on the Portland Early Music Festival, call 775-3356 or visit portlandconservatoryofmusic.org.

Christopher Durang’s Tony Award-winning comedy, “Vanya and Sonia and Masha and Spike,” is the opening production of Good Theater’s 15th season of professional theater in Portland.