"Why" is a hit song recorded by Frankie Avalon in 1959 that went to No. 1 on the U.S. Billboard Hot 100 chart published on the week of December 28, 1959 "for the week ending of January 2nd, 1960", making it the last No. 1 single of the 1950s, and the first No. 1 single of the 1960s at the same time. The single also became the first No. 1 single of the 1960s on the Cashbox magazine charts. The song was written by Avalon's manager and record producer Robert "Bob" Marcucci and Peter De Angelis. It was Avalon's second and final No. 1 hit. The melody is based on an Italian song. The Avalon version features a female singer, which is heard in the repeat of the first four lines of the first part of the song, with Frankie, replying: "Yes, I Love you"., where he concludes the last quarter of the song, with a Coda, by himself.

...
Wikipedia