quarter of a century is a significant milestone: a silver jubilee.

For Diane Wittry, her 25 years as Allentown Symphony Orcestra Music Director and Conductor will be celebrated all-season-long in 2019-2020. It’s a “Season of Celebration.”

During Wittry’s 25 seasons of artistic leadership, the Allentown Symphony has risen to increasing standards of excellence, performing with passion and dedication and honored nationally with the prestigious “American Prize” for artistic quality in 2014 and 2017.

Single tickets for the 2019-2020 season go on sale Aug. 1.

The Allentown Symphony performs its “Classical Series” weekends in Miller Symphony Hall, Allentown. Concerts are at 7:30 p.m. Saturdays. New for the 2019-2020 season, the Symphony performs at 2 p.m. Sundays.

A survey of patrons determined an overwhelming preference for 2 p.m. instead of the previous 3 p.m. Sunday concert starts. This way, concert-goers should be able to return to their residences before dark during winter. It also should reduce traffic congestion on Sunday evenings before the puck drops for Lehigh Valley Phantoms’ hockey games in PPL Center.

The Allentown Symphony Orchestra “Classical Series” for 2019-2020 is five programs of back-to-back performances.

Wittry’s 25th season with the Allentown Symphony has a roster of award-winning guest soloists, timeless masterworks, including Beethoven’s “Pastoral”; an “All-Tchaikovsky” program; eclectic contemporary compositions, with a world premiere by American composer Christopher Theofanidis, and ongoing partnerships with Lehigh Valley arts organizations, including the Allentown Band and Repertory Dance Theatre.

Award-winning soloists include Olga Kern, Van Cliburn Gold Medalist; Drew Petersen, Avery Fischer Career Grant; Irina Muresanu, 1997 winner of the Schadt Competition, along with violinist Lindsey Deutsch, Cathy Yang, erhu, performing Tan Dun’s “Concerto” from “Crouching Tiger, Hidden Dragon,” and ASO Concertmaster Eliezer Gutman.

In observation of her tenure, Wittry has programmed a season of concerts emphasizing Allentown Symphony’s ties to the Lehigh Valley.

“I really tried to bring out wonderful pieces and also to highlight relationships we’ve had with people in the community,” says Wittry of her curating the 2019-2020 season.

“For example, particularly, the final concert, which is the 25th aniversary celebration concert, April 18 and 19, it’s ending with Respighi’s ‘The Pines of Rome,’ which was the very first concert I ever conducted with the Allentown Symphony when I auditioned,” says Wittry, who took over the baton for the orchestra in fall 1994.

“We’re also showcasing the very first winner of the Schadt Competition, Irina Muresanu, violin. And we’re having her perform the same piece that she performed, the Prokofiev ‘Violin Concerto No. 2.’ People still talk about her and her performance.

“We’ re doing the John Rutter ‘Gloria,’ featuring the Allentown Symphony Chorus, which I’m very proud of and which we founded about six ago.

“We’re doing the ‘Concertino for Organ and Orchestra’ by Eric Ewazen, which Allen Organ helped commission. I wanted to pay tribute to the more than 50-year relationship that the Allentown Symphony has had with Allen Organ.

“The opening work is the ‘Festive Overture’ by Shostakovich. And with this piece and ‘The Pines of Rome,’ we’re paying tribute to our relationship with the Allentown Band as both pieces have written-out parts for extra brass.

“In addition, we’re going to have a pre-concert program by our El Sistema musicians, noting its 10th anniversary.”

The 2019-2020 Allentown Symphony “Classical Series” opens at 7:30 p.m. Sept. 21 and 2 p.m. Sept. 22 with Olga Kern playing Rachmaninoff’s “Second Piano Concerto,” plus the Strauss “Blue Danube.”

Wittry complements the “Blue” opener with two contemporary compositions, Michael Torke’s “Bright Blue Music” and Jennifer Higdon’s “blue cathedral.”

“I’m having a little fun with that. We turned it into a blue-tie event for orchestra members,” Wittry says.

“I try to bring the world’s best artists to the Lehigh Valley, both established artists and up-and-coming artists. Olga Kern is a very renowned established aritst.

The season kicks off with a “Rach and Blue” pre-concert event Sept. 21 in Miller Symphony Hall’s Rodale Room.

The second concert in the “Classical Series” is “All-Tchaikovsky - 1812 and More,” 7:30 p.m. Nov. 9 and 2 p.m. Nov. 10.

Drew Petersen performs Tchaikovsky’s “First Piano Concerto.” Repertory Dance Theatre takes the stage with the Allentown Symphony for selections from “Swan Lake.”

The program includes Tchaikovsky’s “Symphony No. 6, Pathétique” and the “Finale” from “The 1812 Overture.”

“Drew Peterson is up-and-coming,” says Wittry.

“In paying tribute to relatioshhips, I invited Repertory Dance Theatre. We’ve done the ‘Nutcracker’ with them.”

The third concert in the “Classical Series” is “Movie Classics - The Sound of Cinema,” 7:30 p.m. Feb. 8, 2020, and 2 p.m. Feb. 9, 2020.

“The February concert is outside the box,” Wittry says. “About two years ago, a member of our chorus sent me a YouTube link of the Danish National Symphony Orchestra performing ‘The Good The Bad and the Ugly.’ He said, ‘Wouldn’t it be fun if the ASO did something like this?’

“That was the first spark of the idea.

“Last May, I was in China giving a talk at a women’s concert. I was asked to conduct a concert. And they had a Chinese erhu player. It’s kind of the equivalent of a violin, but it only has two strings not four.

“And then I thought of doing a concert of Academy Award-winning film composers, but epic pieces.

“We’re featuring composers from 10 different countries, a United Nations of music,” says Wittry.

It will be epic movies and epic music from “Ben-Hur,” “Psycho,” “Lawrence of Arabia,” “E.T.” and “Lord of the Rings.” in other words, classic movies powered by classical music.

The “Concerto” from Tan Dun’s score to “Crouching Tiger, Hidden Dragon” features Cathy Yang on erhu. The Allentown Symphony Chorus performs “O, Fortuna” from “Carmina Burana.” Allentown Symphony Concertmaster Eliezer Gutman plays the tango from “Scent of a Woman.”

“We have the contrast between the violin soloist and the erhu soloist. They’re both string instruments, but totally different in their sound and character,” Wittry says.

Wttry’s putting out a call for extra trumpets, trombones and snare drums for the opening piece, “Ben Hur.” There will be open auditions. Information will be available on the Miller Symphony Hall website.

The fourth concert in the “Classical Series” is “Beethoven’s Pastoral,” 7:30 p.m. March 7, 2020, and 2 p.m. March 8, 2020.

The Allentown Symphony celebrates the 50th anniversary of Earth Day with Beethoven’s Symphony No. 6, “Pastoral.” Violinist Lindsay Deutsch, who has toured with Yanni, performs two other masterworks as soloist on selections from Vivaldi’s “The Four Seasons” and Piazzolla’s “The Four Seasons of Buenos Aires.” There’s also the world premiere of a work by American composer Christopher Theofanidis, commissioned by the Allentown Symphony.

“Chris will actually go to the Wildlands Conservancy [near Emmaus] and be site-inspired for 50th anniverary of Earth Day,” says Wittry.

The 2 p.m. Feb. 22 “Family concert” also has the theme of “Go Green! - 50th Anniversary of Earth Day.”

The Allentown Symphony “Pops Series,” which began with Classical Mystery Tour, July 13, continues with “The Best of Broadway - Stephen Sondheim and Andrew Lloyd Webber,” 7:30 p.m. Oct. 12; “Music and Sports,” 7:30 p.m. Jan. 18, 2020, and “Women Rock,” 7:30 p.m. May 9.

Ticket information: Subscription packages for Allentown Symphony Orchestra 2019-2020 concerts are available. Single tickets go on sale Aug. 1. Box Office hours: 10 a.m.-5 p.m. Monday-Friday. Summer hours (through Aug. 30): 10 a.m.-2 p.m. Monday-Friday, Miller Symphony Hall Box Office, 23 N. Sixth St., Allentown. MillerSymphonyHall; org; 610.432.6715. Allentown Symphony Orchestra tickets for students 21 and under are free.