I can't tell, but I'm going with Piss Report. It's difficult to say because it involves both. Simultaneously. More or less.
The other day at work, I had to take a roaring piss. I had 20 oz glass of water with breakfast and, lo and behold, an hour later, I needed to pee. Of course, like any good bodily function story, I kept gFetting distracted by trivial matters so that I couldn't get to company piss pot. Finally, a half-hour later, with an aching bladder, I was able to get to the Men's Room.
I have to admit that this 4-holer has exceptional acoustics. While I was unlimbering the timber, I felt the urge to pass some gas. Seeing as how farting while pissing at the urinal is almost a given, and since there was nobody there but me, I decided to go loud and proud. So, I let fly right after I started pissing. And what I thought was going to be a reverberating bomb turned out to be a long, slow rumble. And that rumble went on.
And even when I finished pissing (what seemed to be a full minute later), that fart was still blasting away. For fear of disrupting a fart of such epic magnitude, I just stood there letting fly. That concerto seemed to go on for another 30 seconds until it had finally come to its sputtering epilogue.
Once the ass music has ended, I was struck by a kind of sadness that it had to come to an end. I put away my junk, washed my hands and strolled back to my desk, feeling quite smug that I had performed a feat of true beauty.