When NOT to sing -

1. Just before the judge passes sentence
2. During a two minute silence
3. While stalking a grizly bear

el Gnomo, singing just before the judge passes sentence might pan out very well for you. Might even garner you a new trial.

Not that I can say I have tried it.

As for bears and song- some years ago I stopped to rest on a steep winding mountain trail and lingered when I heard a man's voice in fullthroated song some distance down below me. When he and his companion came into view, I called out to him. "Nice voice," I said.

"Just keeping the bears away" he responded, and as they disappeared around the next turn, again his song rose into the air.