This Rodger & Hammerstein classic is one of the most frequently called jam session tunes. And it is probably among the most badly botched. Technically the song is not all that difficult, but the song form is what makes it an adventure. People do this song many different ways, so it is worthwhile to agree on the song form before counting it off.
This arrangement follows the song form you will find in most fake books. There is a long intro -- 16 bars -- to get into the feel. From there, the song form might be called AAB - interlude - C
The two A sections are identical -- 16 + 16 bars centered around E minor.
The B section is 16 bars, mostly in major -- starting in E Major. But the melody is almost the same as the A section. This is possible because the melody works the 2nd and 9th heavily, and those notes are the same whether we've doing Emi9 or EMaj9.
It is important to note that many musicians add a 4- or 8-bar vamp to some or all of those A and B sections before proceeding to the next section. If musicians don't agree on that, it can be a train wreck.
After the B section, there is a short (8-bar) breakdown or interlude where the lyrics are "When the dog bites, When the bee stings ..."
Then we have a final 16 bars indicated here as the C section. That C section includes a short vamp that is almost universally observed. So the full song form in this case is 16+16+16+8+16 = 56 bars.