On Thursday morning, Matthew A. Aucoin ’12 will direct a string ensemble in the premiere of a piece that he composed in about three days, performing for the final lecture of the course Aesthetic and Interpretive Understanding 24: “First Nights: Five Performance Premieres.”

Aucoin is stepping in at the last minute for Michael A. Einziger, a composer and special Harvard student who has achieved fame as the guitarist for the rock band Incubus.

Incubus announced on their website last Friday that Einziger had become ill and they were therefore canceling three shows in Europe. Einziger also backed out of Thursday’s premiere for the First Nights course, which he had been working on with a string ensemble at Harvard.

“I was disappointed, of course, but mostly sorry about Mike, because I know how much he was looking forward to this,” said music professor Thomas F. Kelly, instructor of the course, which examines five famous pieces of classical music and ends with a piece specifically commissioned for the course. “He had taken First Nights in the past and was working hard on his composition study in general. We are all sorry he’s ill, and we wish him well.”

Aucoin, who is friends with Einziger, was already slated to conduct Einziger’s piece at its premiere. When Einziger backed out, Kelly sent out an emergency call asking for last-minute compositions.

“[Aucoin] volunteered that he had a string piece he was working on, and that if he dropped everything he might be able to finish it in time,” Kelly said.

The piece, according to Aucoin, grew from a simple melodic idea to a full-fledged seven-minute piece in about three days. “I had a fragment that I was hoping to turn into a big piece for strings,” he said. “I thought, well, you know, if I really don’t sleep for a couple of days, I can write a piece based on this and arrange it for string orchestra.”

The piece’s hectic premiere fits in nicely alongside the rest of the works surveyed in the course, many of which had chaotic debuts themselves, according to Kelly.

“This new and very beautiful piece gives us a chance to be part of the excitement and frantic rush involved in getting a performance on stage,” Kelly said. “It’s a real-life situation, not a matter of taking a marble monument down off its shelf.”

And some of the students in the course seemed to feel the same way.

“I read [Aucoin]’s bio, and I was kind of excited to have something thrown together at the last minute,” said Maria I. Romero ’15. “I feel like it’ll be a more genuine and raw performance, as opposed to something that’s been polished for a while.”

The piece will be performed at 11 a.m. Thursday in Sanders Theatre.