The Song Fight Bulletin Board

Has anyone ever discussed this? It seems to me as if they fall into several categories at least:

Structural - A challenge that effects the structure of the song itself.
Arrangement - A challenge having to do with the arrangement of the material.
Studio - A challenge that requires some sort of studio trickery.
Delivery - A challenge concerning the performance (mood, speed, etc).
Lyrical - A challenge that affects the lyrics only.

Others?

I always thought of them as either musical or lyrical. However, I accept your sub-categories.

There's also my least favorite: the restrictive challenge e.g. No Guitars. However the no choruses worked out well for the WSA last year.

Here's an attempt at the complete list of challenges. I may have missed one here or there though. It's in chronological order I think.

Must Include Handclaps
No rhyming
Opposite Sex Vocals
Plagiarize from one of the judges
Bass Solo
Call and Response
Bring your A-Game
Unconventional percussion
Must include use of alliteration
Must include a change in time signature
Guest Vocals
No Guitars
Only Vox and Guitars
Song must be more than six minutes in length
Significant Name Drop of an Actor/Actress
Must include use of crescendo
Must include use of backwards recording
Use of choral voices
Three Different Tempos
Must include the prominent use of a kitchen item (such as a pot, pan, glass, mixer) as an instrument.
Must include a phrase in a language other than English, Spanish, Italian, French or German
Must be 2 minutes or shorter and must include 2 verses, a chorus, a repetition of the chorus and a solo
Two sides of an argument
Guest Rapper
Lyrics in sonnet form
Must be Through Composed
Genre Hop
Must include audible counting
Must include whispering
Accelerando
Bring a Guest
Use the sample
Must include an Acrostic
Judicious use of silence
Must be educational
Cannot have a chorus
Must be autobiographical
Duet with a guest
Significant use of cacophony
Creative use of flatline tone
No real instruments
Significant Use of Shouting
Must include a round

Feel free to categorize as you see fit.