Similar to Noel's advice to do the song in a linear format, I begin the song with a 7 bar intro and I use 1st/2nd ending for the first verse/chorus and 2nd verse/chorus and then for a verse of instrumental, I change the style and at the following chorus I change the style back to the original style. At the end of that chorus, I repeat the last two lines "some people claim..." and then use a style change back to the second style and the instrumental plays out to the end of the song.
By using the 1st/2nd ending rather than a single linear format causes BIAB to play a more interesting 2nd verse and chorus without having to use Part Markers to generate different variations of the style. Then by changing the Style to a completely different style adds even more variation and dynamics that continues to build the song arrangement and the song still has the more active B style arrangement on the last chorus and builds again for the two line last repeat and instrumental ending.
Here's a link to the m4a audio of the attached SGU file with no melody or vocals added.
I made no attempt to actually recreate a performance of the song Margaritaville but used two styles found using a filtered search for the song in the StylePicker. The styles used are a/b ISLANDP.STY and c/d CTRYPSS.STY
Margaritaville m4a file in DropBox