Two weeks after selling out Woolsey Hall with its annual Halloween Show, the Yale Symphony Orchestra will return to its classical roots this weekend.

On Saturday, the YSO will present a concert with an “unfinished” theme, featuring works by Franz Schubert, Gustav Mahler and Thomas Duffy, the director of bands at Yale. The theme refers to the pieces composed by Schubert and Mahler, which were not completed at the time of the composers’ deaths. YSO conductor Toshiyuki Shimada, who compiled the concert program, said he believes that the concert’s “unfinished” theme is meant to evoke a sense of longevity and preservation.

“It gives us positive energy to be in an unfinished situation,” Shimada said. “It’s like life. It gives us will.”

Opening the concert is “Heart-Throb” by Duffy, who will conduct the piece himself. Commissioned by the Yale School of Medicine for its 150th anniversary, the piece depicts the life of a patient suffering from a heart condition, according to Ben Healy ’16. He explained that the drums play a rhythm based on the human heartbeat that occasionally shifts to an irregular pattern — a sign that the patient’s heart is unhealthy. The rest of the orchestra similarly alternates between consonance and dissonance depending on the heart’s health, Healy added.

Shimada highlighted the connection between Duffy’s piece and the concert’s central theme. He said that during one of the group’s rehearsals, a YSO musician asked if the patient in the piece dies, adding that the group ultimately decided that the patient survives, or is “unfinished.”

Following “Heart-Throb,” the group will perform Schubert’s Symphony No. 7 — known as his “Unfinished” symphony — with YSO assistant conductor Jacob Joyce ’14. The work is referred to as “unfinished” because only two of its movements were completed at the time of Schubert’s death. School of Music professor Paul Hawkshaw noted that the reasons behind the piece’s incomplete nature are unclear because Schubert mysteriously stopped writing the piece six years before he died.

Joyce encouraged audience members to listen for Schubert’s distinctive compositional style as the piece is performed, referring to the sound of the piece as “ethereal.”

“The melodies are so long, they often feel like it’s totally removed from even the musical world,” Joyce said.

To finish the concert, Shimada will conduct the “Adagio” movement from Mahler’s 10th Symphony, which is also commonly known as his “unfinished” symphony. He explained that unlike Schubert’s work, Mahler’s symphony was intended to be finished, but Mahler passed away from heart disease before he could complete the composition.

Members of the orchestra were especially excited to showcase Mahler’s symphony. Shimada said he is an avid enthusiast of Mahler’s work, noting that the YSO played Mahler’s Symphony No. 2 last year. He added that during the process of selecting the upcoming concert’s repertoire, the “Adagio” was the first piece that came to his mind.

“The one thing that always impresses me is that [Mahler’s] personal character comes alive. It’s like resurrecting Mahler,” Shimada said.

The Yale Symphony Orchestra was founded in 1965.