We all sat in an auditorium with our sheet music and, well, sang along to Handel's Messiah. They had a professional performance of Messiah projected onto a screen at the front of the room so we had a strong lead to follow. There was a dude standing in front of the screen at a lectern, conducting the music, which I thought was a nice touch. Most of the people there sounded like amateurs, like me, but there were a few really talented (and practiced) singers there.
All in all, it was a great time, even if they positively raced through "Surely He Hath Borne Our Griefs." As we were driving home, I decided that this was the nerdiest thing I've done in a long time. As my brother put it, out of a huge pool of nerdy people (computer engineers), the most extraordinarily nerdy people rose to the top...and attended the Messiah sing-along.
And I was there, too, and it was great company, and a great time.