Question: who sings i can't take my eyes off of you?
Answer: Frankie Valli

"Can't Take My Eyes Off You" is a 1967 single credited to Frankie Valli.  The song was among his biggest hits, earning a gold record and reaching No. 2 on the Billboard Hot 100 for a week, stuck behind "Windy" by The Association. It was co-written by Bob Gaudio, a bandmate of Valli's in The Four Seasons. It was Valli's biggest solo hit until he hit #1 in 1974 with "My Eyes Adored You".