"Shipoopi" is a song in the 1957 musical The Music Man by Meredith Willson. The song is sung by the character Marcellus Washburn, friend of Harold Hill. In the play, the song is about finding love and occurs at about the same time that Marian begins to fall for Professor Hill's wooing.
In the 1962 film version of The Music Man, the character of Marcellus Washburn was played by Buddy Hackett. According to the film documentary included with the extended DVD release, choreographer Onna White was able to take someone not well known as a dancer, and make him (Hackett) a dancing star for this number.
The surrounding dialogue does not specify the meaning of the term shipoopi, which Willson invented for the song. The chorus implies that it means a "girl who's hard to get", and the first stanza says a woman who waits until the third date to kiss is a shipoopi.
The solfege used by the chorus deviates from standard English-language solfege in several ways; within the context of the musical, some or all of these errors may be attributable to the fact that Marcellus, a former con artist, does not have formal musical training in his "professional" background.
The chorus sings "Do re mi fa so la si do" despite the fact that the work of John Curwen had earlier substituted "Do re mi fa so la ti do" as the English standard. The syllable si is generally used for a raised 5th (instead of sol) or a g#, in the fixed do system. (Although si is commonly used for the 7th scale degree in non-English speaking countries.)
With regards to the tonal context of the song, while the Chorus sings "do re mi fa so la si do - si la so fa mi re do", the actual scale degrees are "sol la ti do re me fa sol - fa mi re do ti la sol." The line actually begins and ends on the 5th scale degree creating a half cadence. The second time the chorus sings the following line: "do re mi fa sol la si do - si do". However, the actual scale degrees sung by the chorus are "sol la si do re mi fa sol - sol do" creating a proper full cadence tonicizing do.
At one point, the chorus sings the phrase "do-si-do," a basic dance step (sometimes called a dosado), but the note for this "si" syllable does not fall on the "si" of the Solfège scale.