Conductor Erik Ochsner believes in the five Ps — proper planning prevents poor performance.

“For me as a conductor, I like knowing more about the piece,” he said. “It’s not just notes on the page. I want to know the history. I want to know stylistically what was going on (when it was written) … I’m a servant to the score, and this week I’m a servant to Mahler, Mozart and Strauss.”

Ochsner will lead the Youngstown Symphony Orchestra for a concert Friday featuring works by those three classical titans.

For the overture to “Der Fledermaus” by Johann Strauss II, the music is part of an operetta, and Ochsner said he studied the words that would be part of a staged production to better understand the composer’s intent and have the music reflect that.

David Allen Wehr, dean of the Mary Pappert School of Music at Duquesne University in Pittsburgh, will be the piano soloist on Wolfgang Amadeus Mozart’s Piano Concerto No.23 A major. Ochsner has conducted Mozart compositions before, but it will be his first time conducting this piece.

“He wrote 626 pieces before he died at 35,” Ochsner said. “He was a machine — pristine, crystal clear and virtuosic. If I said those words to my conductor friends, they would say you have to be describing Mozart.”

The evening will close with Gustav Mahler’s Symphony No. 1 in D Major. Ochsner said the work “changed the idea of what a symphony could be,” and the tone poem in four movements explores a range of ideas and musical styles, influenced by folk tales and other composers.

“Mahler was one of the preeminent conductors at the time, so he wrote lots of stuff in the score. He makes notes for the conductor — don’t rush, slow down. If Mahler as a conductor put in a metronome mark, maybe we should consider that’s what he wanted. I try to be true to the composer.”

Friday will be a return engagement for Ochsner, who conducted the Youngstown Symphony Orchestra last season for two performances providing live musical accompaniment to the 1984 movie “Ghostbusters.”

“You know if you’re coming back there was a good connection with the orchestra,” he said. “When they asked me to do this kind of repertoire, I was flabbergasted. I had to read the email two, three times to make sure it was true.”

Ochsner — who attended the Pierre Monteux school, graduated from Dartmouth College and is founder and music director of the SONOS Chamber Orchestra — is best known for his work with film scores. He’s conducted programs where orchestras accompanied films ranging from the original “Star Wars” trilogy to “Pixar in Concert.” He was the principal touring conductor for “La La Land Live in Concert,” leading 50 performances worldwide.

The job is the same, he said, whether he’s conducting work by Mozart or John Williams. Many of those modern film composers are classically trained and influenced by classical music, and those performances introduce live orchestral music to a new audience

“We’re employing musicians, entertaining audiences, serving our communities,” he said. “It all comes down to exposure and something I call the fear of the unknown. They might fear sushi, but have you ever tried it? They might have heard that Mahler is hard, but they should try not to be afraid and expose their family and their children to something new.”

If you go …

WHAT: Youngstown Symphony Orchestra with Erik Ochsner, guest conductor, and David Allen Wehr, piano

WHEN: 7:30 p.m. Friday

WHERE: Stambaugh Auditorium, 1000 Fifth Ave., Youngstown

HOW MUCH: Tickets range from $22 to $52 and are available online at stambaughauditorium.com and by calling 330-259-9651.