Believe it or not, I am a fan of artists pushing boundaries and buttons. If this was Leon's goal, he succeeded. Most of the attendees I spoke with were bored and/or annoyed with his show.
At first, I thought his mentioning about wanting a "Sing-Along" song was a funny commentary on how no one seemed to know the words of what he was singing. But after, oh... the 58th time he mentioned it, the charm was long gone. During the night, Leon kept asking the piano player what song he should play: 90% of the time he would follow it up with "Is that a Sing-along song? Oh, that's a good one. That's a good sing-along song. What key is that in? F? F... for Failure." Funny the first time, not funny after repeating it half a million times. It would have been all the forgivable if he would have followed up the joke by playing the actual song. Unfortunately, that only happened a few times. Instead, he'd repeat a few bars on his guitar of some other song that was in his head and then the whole process would start over again. I didn't count how many songs he actually started and finished, but I would make a guess that it was about 10 songs (that lasted about 3 mins each) over a 2 hr period.
The songs he did manage to complete, were lovely. He's a great guitarist and a wonderful singer... In fact, I think it was because of these brief moments of actual musical performance that I felt so disappointed about the overall show: they were tiny, infrequent reminders of how amazing the night could have been.