Standing next in turn in good mood; finished "Straight, No Chaser" with a fast tempo.
What the Thelonious are we describing?
I was trying to find something quite complicated, but soon got the feeling that something was
You're up (next in turn)
Not feeling down (in good mood) (trying to avoid unfortunate mix-ups by this choice of words)
time's up (finished)
Straight up (served with no ice and no chaser)
uptempo (with a fast tempo)
And since we are clearly on the theme of music here, I'm guessing this is the final answer that OP was trying to sneak past us.