"Ain't No Big Thing" was almost an unofficial second theme song for the first season. It was written by Kui Lee and recorded by many performers, including Don Ho, the Brothers Cazimero and Kawika Crowley.
McGarrett alludes to the song previously in "....And They Painted Daisies On His Coffin" (#1.5) when he tells Big Chicken, "Ain't no big thing, brother." In "The Box" (#1.16) Big Chicken sings it in the shower.
The title is based on the Irving Berlin song and movie Blue Skies (1946) that starred Bing Crosby and Fred Astaire.