TubeNet

Yes, it was written In an afternoon. The best thing to do is ask him.

I seem to remember a TUBA journal (I think it was pre-ITEC) by Mickey Wrobleski that gives some insight.

I've read the Wrobleski article. It has a lot of good tips and a list of errata in the published version that goes against Penderecki's original manuscript. That being said, I've always heard the (apocryphal?) story that it was written in 45 minutes. But that might be exaggerated.

On a related note: while the infamous Capriccio might not be the most pleasant listening experience to most people, I think it is always fun (to me) and beneficial to push the capabilities of you and your instrument (especially in regards to wide leaps and advanced technique found in this piece), regardless of whether or not you have an appreciative audience (or any audience at all). There's a really interesting discussion to be had here, regarding whether music (yes, including tuba solos) should be thought of as performance art with the audience (and what the audience will like) in mind, or as introspective declamations of "yes, I can play this, master this, perform this, and own this" with less regard to whom you're playing for.

arp "tootin' in the ivory tower? " thark

No history here, an maybe I am influenced my the first recording I heard, but I do like Perrantoni's version on "Lion's Den". LVJ, the is aim very nice energy and crazy dynamic
Interpretation (read good risk taking) in your version. Now I need to go and listen to more recorded versions of this fun little ditty.