The Song That Goes Like This is a song written by Eric Idle from the musical comedy Spamalot. The song's melody is intentionally treacly and insipid, and is essentially a parody of the love songs written by composers like Andrew Lloyd Webber.
The singers sing about the one song that occurs in every Broadway musical, and its defining features (incredibly long, changing musical keys, and extremely high notes, the male lead at one point complaining that "Now we're into E, that's awfully high for me. But everyone can see, we should have stayed in D."). In the Broadway production of the musical, a chandelier appears above the singers, an additional parody of The Phantom of the Opera's famous song. At the end of the song, the singers hit a note so high that it seems to shatter the chandelier.
Once in every show
There comes a song like this
It starts off soft and low
And ends up with a kiss
Oh where is the song that goes like this?