Tubby misbehaves at rehearsal, and the conductor tells him to leave. Defiant, Tubby joins a marching band. It's fun at first, but all the marching finally wears him out. He can't even OOM-PAH anymore, and he longs to get back to the orchestra. Tubby escapes and runs home once again where he finds that all his friends missed him, too! Tubby realizes he belongs in the orchestra, and it makes him very happy

Tubby (Tim Hauser)
I want to be seen
I want to be heard;
My dream has always been
To sing like a bird
Why can't I be
Content to just be me?
Why can't I be
Just the best that I can be?
I don't like to see me
Feeling so unhappy;
I would much rather see me
Very, very happy

Tubby (Tim Hauser)
Oh, the duty of a tuba
When the others sing, "Tra-la,"
Is to sound just like a tuba
And say, "OOM-PAH."
But when you've got to march all day
Not only march, but also play
You start to lose your breath and huff
And instead of "OOM-PAH,"
All you say is "Puff,puff, puff."
I'm a very sad tuba
'Cause I've lost my OOM-PAH
Nothing's left for me to do now
But go, "Puff'uff'uff"