The last time I sang...
Depends on the context. I have pitch but can't carry a tune and am horrendously off-key.
The last time I sang in church was two weeks ago, I believe.
The last time I sang in a non-church setting was in my car, driving home from work on Friday. I tend to turn the radio up high and sing. Especially when it's warm, cause then I get four-speed air conditioning (open four windows and speed ;) ) and it's so much better for the throat than dry winter air.
I think I sang to a young woman I was dating in July or so. She is a trained singer and had asked me to sing. I think I sang the Star Spangled Banner.
Then again, I might have sung to my nieces shortly before or after that, during my trip to Texas in late July. The Wheels on the Bus! ;)