“Bowing” (how the bow is used on an orchestral stringed instrument) sounds the same as “Boeing” (the name of a company that manufactures airplanes). There is a joke about it:
   
Q: Why is a violist like a terrorist?
A: They both fuck/mess/screw up Boeings/bowings.
 
The joke has been cited in print since at least 1992.
 
       
Wiki—YoungComposers.com
Bowing technique
Bowing describes how the bow is used on an orchestral stringed instrument. For the violin, viola, ‘violoncello, and double bass, the bowing techniques are largely identical with only minor differences. The bow is held in the right hand and drawn perpendicularly across the string at a point somewhere between the end of the fingerboard and the bridge. Exactly how and where the bow is used allows for a variety of timbres and articulations with each their own characteristics and a good string player is expected to have mastered each of the fundamental techniques and their combinations.
 
Wikipedia: Boeing
The Boeing Company (/ˈboʊ.ɪŋ/) is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets and satellites. It also provides leasing and product support services. Boeing is among the largest global aircraft manufacturers, is the second-largest defense contractor in the world based on 2013 revenue, and is the largest exporter in the United States by dollar value. Boeing stock is a component of the Dow Jones Industrial Average.
     
Google Groups: rec.music.classical
Musical jokes
“Vinay K. Chaudhri”
7/31/92
(...)
Why is a violist like a terrorist?
They both **** up bowings.
 
Google Groups: rec.music.classical
finally - the joke list. . .
susan poliniak
11/10/93
(...)
Q - Why is a violist like a terrorist?
A - They both f*ck up bowings (Boeings - get it?).
 
Google Groups: rec.music.classical
Musician jokes v2.0
boB
9/1/94
(...)
Q: What do a bad airplane mechanic and a violist have in common?  A: Both screw up Boeings.
 
Google Books
The Musician’s Joke Book:
Knowing the Score
By Nancy Groce
New York, NY: Schirmer Books; London: Prentice Hall International
1996
Pg. ?:
Why is a violist like a terrorist? They both screw up Boeings.
 
Google Books
“The Kushmaker” and Other Essays on Folk Speech and Folk Humor
By Alan Dundes
Edited by Wolfgang Mieder
Burlington, VT: “Proverbium” in cooperation with the Dept. of German and Russian, University of Vermont
2008
Pg. 166:
How is a violist like a terrorist? They both mess up bowings [Boeings].
 
Twitter
Helen Innes
‏@__harymelen
Why is a Violist like a terrorist?
They both screw up bowings. (Bowings/Boeings ... Get it?)
4:31 PM - 4 Feb 2011
 
Twitter
MSI
‏@msi_school
Q: Why is a Violist like a terrorist?
A: They both screw up bowings. (Bowings/Boeings ... Get it?) Smile.. Only Jokes for Wednesday
10:57 PM - 2 Oct 2012