What it feels like to play a tuba
An excellent description of what it is like to play a tuba - from Jay's Tuba page

Range When you're blowing this much air, there's no oxygen left for your brain. The tuba is a bass clef insturment. If you try to compete with a flute to see who can get higher, you'll lose - or pass out trying. The plus side is a "natural" high feeling.
The warning zone. When you start to get a woozy feeling, but it passes when you head back down into the green zone.
Ahhh... The comfort zone. No odd things should happen to you here. The majority of notes actually played by the tuba are in this range. Occasionally other ranges slip in, but mostly the others are for show.
Have you ever blown bubbles with your mouth underwater? About the same feeling as you get here.
Slap two hot dogs together as fast as you can. Now imagine that those are your lips.

Tuba Quotes

Tuba Sizings

Q: What is the meaning of expressions of the type "4/4", "6/4" and so on for tuba sizes?

A: Tubas come in various sizes, using a system of 1/4ths, 3/4, 4/4, etc.. However the determination of the actual size is an inexact science. One definition that could help is:

Tubas in the Moonlight

From the Tadpoles album by the Bonzo Dog Doo-Dah Band

Through the twilight, I can hear the humming of a melancholy coon. (mm-mm)
Of the memories that still linger, I thank you mister Moon.
And, although I've never smiled,
Winter, summer, autumn too,
Now here's one tune to remind me why I feel so blue-oo...

Tubas in the moonlight, playing for me all night,
Tell me what I want to hear.
Am I only dreaming?
Am I only scheming?
Stars above me, shining brightly.
Why can't she be sitting here beside me?
Tubas in the moonlight will bring my loved one home.

[instrumental verses]

Tubas in the moonlight will bring my loved one home.