Had to gig last night so no not much time yesterday.
I just listned to THE SKA music of your son.

Allthough it's not my style of music I do like the songs , refreshing and a kind of positive "have fun" feeling with it.
Note: the trumpet needs to practice his timing...that's not meant negative but just as an advise.
If it's played tight it will lift the songs to real swingin'..

Alex,
You shuld not borrow the money to your son for the amp, but give it away he's good enough