The tuba isn't your everyday item. There are images that come to mind when you think of the word Tuba a few images spring to mind (aside from just the image and the deep tooting sound):
Whatever tuba makes you think of, go with it. Possible options would be writing about or from the perspective of a tuba player, a meditation on the sound of the tuba (and perhaps how it came to be that you are hearing the tuba in the first place), or even a vignette about the item that is a tuba with it's curves, colors, shine, etc. Whatever the tuba makes you think of. Here are a couple tuba songs to get you in the mood: The Super Mario Brother's Theme Song, Sonic Boom (kinda loud), El Troquero Locochon, and, well, it kinda sounds like a tuba sampled in The Chicharones' Bring Out the Clowns.
If you want to set other limitations for yourself you could:
a) begin and end with the tuba
b) never use the actual word tuba
c) write it in a series of eight sentences that fluctuate how many words are in them: Sentence 1=7 words, S2=4 words, S3=12 words, S4=9 words, S5=10 words, S6=2 words, S7=7 words, S8=2 words.
Best of luck notebookers!
