No, but I played drum set with an symphony orchestra when it drizzled. We were under a covered stage but my drums were on the north edge. There was a slight breeze from (guess where) the North (you guessed). My drums being acrylic were impervious to the drizzle but the cymbals got wet and the floor tom head filled up with water. Every time I struck a crash or my floor tom it looked like a production of "Stomp". The tuba player who sat in front of me wasn't too happy either.
Having played an outdoor festival where the rain was blowing in from the side under the canopy, I doubt a cymbal would help. At that festival, I was playing guitar and was at the far left of the stage. The speakers were covered in plastic (it was interesting how little that affected the sound) and they threw some plastic over the side of my amp and over my Furman pedal board which has an AC supply built in. I had to lift the tarp with my foot to switch things in the middle of songs. The rain was kind of on and off so they kept the festival going. Although the headliner was War right after us and their road manager refused to let them on. So we ended up closing the show.
Many many years ago I remember playing in SF in such bitter wind that my strings felt like barbed wire and we had to nail down the cymbal stands. The didn't blow over, they just kind of slowly took off. Like a UFO with a long tail hanging beneath it. Zildjian kites.
I've played several outdoor shows with rain/drizzle. Always freaked me out, but I thoroughly wiped my drums down and let them dry at home. No problems yet. I did play a run of Singing In The Rain where they used a rain system on the stage. My percussion setup was located half covered and half uncovered, and the water got on lots of my stuff. It really did an interesting number on one of my cymbals, a weird watermark/patina thing.
As an umbrella? That might be a humorous prop, but not very effective unless it was quite large in diameter.
Never played acoustically outdoors in the rain, and any show using electricity onstage shouldn't go on, either. Water pooling onstage and coming in contact with electrical connections is pretty dangerous. I think even Woodstock shut down during the rain.