Hiccup
Buddy Holly was known to be the first artist to have a" hiccup" in his music. A hiccup is when the singer makes his voice high and low creating a hiccup sound. This was also used later by other artists like Bob Dylan and Paul McCartney. In this video Buddy Holly used the hiccup, so if you listen closely you can hear it
Please watch from a 1:10-1:55.