Constructive Approximation Puns

Yesterday I was doing Concert practice - fairly standard for a music student, play some songs (with a band), receive some constructive criticism, if there's time, play it again, see if it improved.

So after aforementioned criticism the band and I are about to play again when one of the singers points the mic at the speaker (accidentally) and painfully loud feedback assaults our ears.

In the following silence, I commented: "That's the least useful feedback we've had all day!"

...silence.

Then approximately forty people groaning in unison, which gave way to applause for my awful dadjoke.