A tuba has a limited musical range, so a popular tuba joke goes:
   
Q. What’s the range of a tuba?
A. Twenty yards, if you’ve got a good arm.
 
The joke has been cited in print since at least 1993.
 
 
Google News Archive
7 February 1993, The Day, “Have Ear, Will Travel” by John M. Doyle (AP), pg. E2, col. 5:
Backstage at the Kennedy Center before a concert he (Lewis Lipnick—ed.) reels off joke after joke: “What’s the difference between a cello and a coffin? A coffin has the stiff on the inside,” or “What’s the range of a tuba? Twenty yards if you’ve got a good arm.”
 
Google Groups: rec.humor
Canonical List Of Music Humor (part 1/1)
Her Jangle Is Wide Angle
10/14/93
(...)
What’s the range of a tuba?
20 yards if you’ve got a good arm.
 
Google Groups: rec.music.classical
Musician jokes v2.0
boB
9/1/94
(...)
Q: What’s the range of a tuba?  A: Twenty yards, if you’ve got a good arm.
   
Google Groups: rec.music.bluenote
Let’s have some more music jokes!
Mark Garvin
8/29/95
(...)
What’s the range of a tuba?
About 20 yards, if you’ve got a good arm.
 
Google Books
Somebody’s Got My Robe
By John Yarrington
Nashville, TN: Abingdon Press
1997
Pg. 80:
Q. What’s the range of a tuba?
A. Twenty yards, if you’ve got a good arm.
 
Google Groups: alt.fan.chris
Re: Tuba Jokes
WingedMessenger
6/7/08
”::darkshadows::”

wrote in
news:f61j4493f5dpcj9kakqcjuggulj2s6igfj@4ax.com:
>
>
>
> Tuba Jokes
> =======
>
>
> What’s the range of a tuba?
>
> Twenty yards if you’ve got a good arm!
 
Twitter
Miranda Woodward
‏@XMPWX
A Little Musical Levity - boxangle: Q. What’s the range of a tuba? A. Ten yards, if you have a good arm…. http://tmblr.co/ZKwp0uvjOiX3
10:36 AM - 22 Sep 2013
 
Twitter
MusicianHumor
‏@JokesBoutMusic
What’s the range of a tuba?
Twenty yards if you’ve got a good arm!
12:08 PM - 16 Feb 2015