Lee Hi and Psy sang 'What Should Have Been' together.

At Psy's concert 'Happening' held in Seoul today, Lee Hi appeared as a guest.

On this day, Lee Hi wore a white dress and appeared on stage, catching much attention. Lee Hi together with Psy sang Psy's song from his 6th album 'What Should Have Been,' impressing many in the audience.

Lee Hi and Psy are agency family members, as both of them are currently part of YG Entertainment.

Photo Credit: Xports News