This question has been posed to me quite a few times in my experience with forensics, so if this thought has ever formed in your mind you are not the originator. If you are new to forensics, and have a creative mind, you may have already realized that genre bending adds a unique twist to your piece. For example, a selection that has a few meters of song can help elevate you above other performances just because you are daring. Yet, not all blending of Prose and Poetry is welcome or necessary.
Traditionally there is a clear answer to this query. If you are performing verse you would compete in Poetry; anything non-verse would be Prose. Reflecting back on my years competing in Illinois’ speech circuit (with the Illinois High School Association establishing rules), I recall there were certain materials permissible for Prose and Poetry. Prose detailed that source material could only be of printed works from novels, biographies, short-stories, letters, and non-fiction. There was also a rule that only 50% of your piece could be dialogue. Poetry was more open-ended on what was allowed, but all selections had to be from printed material. Basically Poetry was anything being of verse. Most Poetry pieces would be found from poems or song lyrics. (Although the above information is directly related to rules in Illinois, this does not lessen the merit of them applying to the majority of forensic leagues across the Nation).
Even with knowing where to get pieces from, this still does not answer at what degree a poem become prose, or vice versa. I could not find a percentage listed in any rule book. That leaves any decision to human judgment. And with human judgment there comes human error. My suggestion would be that if you have to question whether or not a piece is Poetry or Prose either make a decision and see what coaches and judges say or do not do the piece. Poetry and Prose should be clear cut and fit into their categories distinctively. I understand modern writers like to test the boundaries of tradition and form, but this cannot be done in a speech round. Regulation is needed to have fair judging. Sorry.
If you find yourself reading a piece and loving it, yet unable to decipher if it should be a Prose or Poetry selection ask yourself this: which does it contain more of? And do not be fooled by blank verse looking like Prose. Once you find this answer you will find what category you should compete in. If you still cannot, nor anyone else, abandon the piece and admire it as art.
Further questions to ponder are if the blending of Prose and Poetry is necessary. Does it add anything to the piece or does it inhibit? Are you trying to find a piece that is different just so you can be labeled ‘edgy’ or ‘distinctive’? Sorry, but if the piece stinks no amount of ingenuity can save you. Select a work because it truly is fantastic and worth everyone’s time.
Ultimately, all decisions lie with you. Choose carefully and make a judgment you can defend. Because if you are performing a piece that judges deem Poetry, yet you call Prose, your rank WILL be at jeopardy even if you stuck all the landings. You need to justify to yourself that you did what you thought best because no one else will care. Unfortunately, this most likely will be the end of that Poetry as Prose, but at least you will have your integrity intact and be able to move forward.