Thank you, Liz!
Tony

Not arguing!

That’s great, Joyce.
Thanks,
Tony

Thanks, Annie!
TC

Let’s say your story starts out sad and frustrated, and ends up determined and hopeful. First verse, sad and frustrated. Second verse, sadder and more frustrated. Then comes the point at which the feeling changes, has to change or you’ll burst. That point is the climax of your song. The climax is the function of your bridge. That’s where the notes go to the highest pitches, and that’s where the lyric reaches a new viewpoint. Last verse involves some kind of resolve to do better (or to give up). That’s why it’s an AABA.

If your song doesn’t involve a change of emotion, you won’t need a bridge. An ABABAB, for instance, doesn’t involve movement. Traditional blues often has no movement because it’s about a life with severely limited choices. The “I” in the song doesn’t take a journey from one emotion to a different emotion. So there’s no need for a bridge.

Yes, you’re the writer and you choose the song’s structure. When I don’t know what I’m writing about — and I sometimes don’t know, I’m just writing to see what happens — then I try to let the song lead me. As the story begins to make itself apparent, I pick the structure that will serve the song. I try not to think about it until I get it all thunk. I let my heart be open to the story being told, and I try to serve the song.

Rich,
As always, thanks for reading and commenting. Great additions to the post.
Best wishes,
Tony

Also, a bridge need not be a full song section to have a refreshing impact. A “bridge” can just be a clever hooky 4 bar instrumental, or a chant over a drum beat, or a sung couplet, etc.

Another question when contemplating a bridge: Sometimes a bridge is an opportunity for a shift of perspective. If the verses are looking at the past, the bridge can look at the future. if the verses are aggressive, the bridge can be thoughtful. If the verses are optimistic, the bridge can be cautionary, etc. So you could ask the question: “Is there something about a brief shift of perspective that would improve the song, or would it just be an unnecessary complication?”