Come on - let's stop picking on Jeanne. Yes it sounds a bit absurd that trumpet players would come to a tuba teacher but let's let her off the hook.
Ray Still, former Pricipal Oboe of the CSO used to require all his students to come to Jacobs for a lesson or two. Now, there is no two instruments farther apart as far as air usage goes that the tuba and oboe! Many years ago, I went to a masterclass by Mr Still. The first thing he did in the class was have people introduce themselves. When the class found out I was a tuba player, they were shocked - everyone except Mr. Still. He said "I send my students to Mr Jacobs why not have his students come to me." I definatly learned something.
Yes, there are times that sitting in a class with another instrument's master teacher can be a bore. I remember sitting through Barry Tuckwell giving a 15 minute lecture on holding the horn. That is the price to pay sitting through a class like that but I walked out the door a better musician.
I know that the concept of borrowing material and concepts from other instruments is not very common with trumpet players. There is a very fine library of music written. For tuba players it is different. We borrow from trombone, cello, horn, and even other instruments such as flute and, yes trumpet. Mr. Jacobs took classes at The Curtis Institute with Macel Tabataeu, oboist of the Philadelphia Orchestra. Here he would prepare music from everywhere, the violin solo from Scherherazade, One fine Day From Madame Butterfly. This is where he learned his great musicianship.
He taught all of us to be a musician first then a _____ player. A great musician is a great musician that you can learn from no matter what instrument they play.
Finally, Mike Anderson refered to the Jacobs Tribute. While no recording was made, I have most of the speeches given that night on my web site - for those who could not be there, take a look.