Yakety Sax" is a pop-jazz instrumental jointly composed by James Q. "Spider" Rich and Boots Randolph. Boots Randolph, a saxophonist, popularized in his 1963 recording. Comedian Benny Hill later made it more widely known as the theme music of The Benny Hill Show.
Yakety does appear to be the correct spelling
I took this from the Benny Hill theme in another thread.
I noticed the bridge was different (or wrong) in that chart so this is the update with the proper name.
Note the song is really When The Saints Come Marching In ...in 2 keys G and C. Yakety Sax - Boot Randolph