A trumpet is played by blowing it, not sucking it. A joke was posted on Twitter by Eric Martin on June 7, 2011:
 
“If you suck at playing the trumpet, that is probably why.”
   
       
Twitter
Eric Martin
@MrEricMartin
If you suck at playing the trumpet, that is probably why.
4:52 PM - 7 Jun 2011
     
Twitter
Colin Sauer
@ColinDusty
If you suck at playing the trumpet, that is probably why.
4:56 PM - 27 Jul 2011
 
Twitter
Eric Martin
@MrEricMartin
If you suck at playing the trumpet, that’s probably why.
7:45 PM - 5 Sep 2011
 
Twitter
Eric Martin
@MrEricMartin
If you suck at playing the trumpet, that’s probably why.
4:41 AM - 28 Feb 2012
     
Google Books
5,000 Sidesplitting Jokes and One-Liners
Compiled by Grant Tucker
London, UK: Biteback Publishing
2013
Pg. ?:
If you suck at playing the trumpet, that’s probably why.
 
Reddit—Jokes
If you suck at playing the trumpet,
submitted January 17, 2018 by Jononator1
Thats probably why
 
Reddit—Dad Jokes
If you suck at playing the trumpet (self.dadjokes)
submitted September 9, 2018 by metnem
That’s probably why.