Will Ferrell spoke at USC's graduation on Friday . . . and busted out some WHITNEY HOUSTON for their listening pleasure.
He told them, quote, "I just want you to know you will never be alone on whatever path you may choose. If you do have a moment where you feel down, just think about the support you have from this great Trojan family.
"Imagine me . . . literally, picture my face . . . singing this song, gently into your ear." Then he sang "I Will Always Love You".
He also "sang" the "Star Trek" theme . . . which he said he used to open his standup comedy shows with, way back before he was famous. He was funny, but he had a serious message, too. He said, quote, "Enjoy the process of your search without succumbing to the pressure of the result.
"Trust your gut, keep throwing darts at the dart board, don't listen to the critics and you will figure it out."