For most of the performances, musicians played behind a screen, so judges evaluated only the sound and not the person. But in his final two performances, Robert was face to face with conductor Esa-Pekka Salonen.
Gupta dug down once more, trying not just to play the piece, but to feel and interpret it. If his boldness cost him the job, so be it.
By the end of the night, Salonen had made his decision. Gupta and David Chernyavsky were the winners, and Gupta would be invited back the following week for tryouts with the full orchestra.
After just three concerts, Gupta was called to the conductor's office.
"I'm very honored to offer you the position," Salonen said. "Will you accept?"
"Absolutely," Gupta said.
Here's what Salonen told me about why he hired a 19-year-old kid for his world-class orchestra.
"I was struck not only by the sheer quality of Robert's playing, but also by the boldness and confidence of it, which is kind of rare at that stage. . . . Many people who come to audition are trying to play it safe . . . and it's playing that . . . is quite often not very interesting."
I wondered, though, if Salonen might be worried that he would show up to work one night and see an empty seat in the orchestra because Gupta had gone off to run Cedars-Sinai Medical Center.
"In a sense," Salonen said of Gupta's far-ranging interests, "this made me even more confident about his future in music, because very clearly Robert is not playing violin in the L.A. Philharmonic for any other reason than his love of music."
In concert at Disney Hall, Gupta appears to have settled in comfortably but lost none of the exuberance. After a recent performance of Beethoven's 4th, he stood Boy Scout proud, basking in warm waves of applause. Last week, he passed his first season of probation with unanimous support from his colleagues.
"He's really a joy to be around," whatever the topic of conversation, said principal concertmaster Martin Chalifour, who finds Gupta's music "enlightened" and "aesthetically beautiful."
Gupta said he looks forward to the occasional solo opportunity, playing chamber music, and perhaps competing one day for a higher position in the orchestra. When he's off duty, he studies literature and science on his own.
Is there still a chance he'll be a doctor one day?
"My wife and I gave up," Vivek Gupta said. "Whatever he decides will be fine. And without music, he would go crazy."