Two undergraduates wrote a computer program Tuesday night to access a hidden promotional image of rapper Tyga on yardfest.org just hours before the website said it would reveal the artist set to perform at the annual spring concert in Harvard Yard.

Tyga, known for the hit “Rack City,” has already been booked to perform as an opening artist at the University of Pennsylvania’s Spring Fling concert on April 12. Harvard’s Yardfest will be held on April 13, according to the Mather House calendar.

Emails sent out over House lists Tuesday evening publicized the website, which featured a ticking clock counting down to a reveal of the 2013 Yardfest artist at 8 p.m. Wednesday night. The website was sponsored by the College Events Board and the Harvard College Concert Commission.

When Kirkland resident Kendall L. Sherman ’15 saw the publicity email sent out over her House list, she set to work trying to crack the website’s code in order to determine the identity of the artist. She was soon joined by her friend Balaji Pandian ’15, a computer science concentrator, who helped write a script to comb through the site for evidence of the Yardfest artist’s identity. Reasoning that the website’s coder had likely named the file that would ultimately reveal the artist in a discoverable way, Pandian wrote a script that scanned through potential file names of photos on the site. Pandian discovered the Tyga photo after running his program for approximately 15 minutes.

Shortly after midnight Wednesday, Sherman sent an email over several House lists revealing the search’s findings.

“Couldn't you guys have not been tools about it so we didn't have to do this? Props to Balaji Pandian,” she wrote.

Sherman said in a phone interview early Wednesday morning that no one from the CEB had reached out to her or Pandian since they disseminated their discovery.

Larson C. Ishii ’15, Secretary of the CEB and a member of the Yardfest Committee, wrote in an email to The Crimson early Wednesday morning that the CEB was “currently looking into the matter to figure out exactly what has happened.”

He added that the CEB was “unable to confirm or deny who the Yardfest artist is” due to contractual obligations.

—Laya Anasu contributed to the reporting of this article.

—Staff writer Amy L. Weiss-Meyer can be reached at aweissmeyer@college.harvard.edu. Follow her on Twitter @amyweissmeyer.