Where do I find a cannon for the 1812 overture?

Setting off some black powder at the same time would add to the effect.

During my short-lived adventure as a professional musician, the symphony I was in went this route and used a stack of subwoofers. I was disappoint.

Some military units have a small cannon that shoots blanks, specifically for the purpose of firing ceremonial salutes.

If your local college has an ROTC program, or your local high school has a JROTC program, they might have one, or know where you can get one.

No recording compares with the real thing. You can’t get the attack, the volume, or the visceral thump-in-the-chest.

It’s a darn good thing nobody has written a symphonic piece to commemorate the last moments of the Hiroshima Philharmonic. Staging that with full sound effects would be especially challenging, even for pros.

Oh, and be sure to have your son listen to P.D.Q. Bach’s 1712 Overture at some point before the concert. Anyone with a bit of familiarity with the 1812 Overture should find it amusing.

and a big choir, and a military band. But no kitchen sink.

Off topic
In the first car I ever worked on with a high end aftermarket CD player system installed, the owner had a CD of the 1812. The CD had a warning on the cover that said it contained digitally recorded cannon fire and could damage you system.
It was marvelous. The cannon fire was from channel to channel. Left then right.

Practice! you need practice!

Here’s a chance to practice

I’ve often seen it done with someone popping hydrogen filled balloons with a flame at the end of a long pole. (Standing outside the hall of course). It’s easier to time correctly than a cannon.

Seriously? That money won’t even pay for the gunpowder! Let alone the transportation.

One result of a Google search suggested that you’d need sixteen guns, because of the amount of time needed for reloading and the close timing of the shots.

Years ago, Mike Royko wrote a column in which he suggested performing the 1812 Overture with people who lived in Chicago using handguns, slang for which at the time was “cannons”. Instead of church bells, he suggested car alarms and anti-rape whistles.

Sorry, I wasn’t able to find a link.