Great Last-Minute Seats

Item 1. Last summer, my wife and I were in New York, standing across the street from Radio City, holding our tickets to a concert that would start in less than an hour. Just then, a girl (i.e., a female under 25) came running from across the street and squealed to her friend how she had just bought tickets to the show at the box office. I realized from her description that the tickets she'd just gotten were better than the ones I had ordered on-line two months before.

Item 2. The next morning, we were wandering through the city when we happened upon the theatre that hosts the musical "Chicago." She's not that into musicals, but said she'd love to go see this one. My expression said, "Are you kidding? There's no way we're gonna walk into this theatre and get seats to a show for anytime this year." But we were feeling adventurous, and didn't care if strangers laughed at us. Five minutes later, we walked out of the box office with 14th row, center-section tickets to the performance for that afternoon. When we attended said show, we got the distinct impression that everyone around us had ordered their tickets weeks if not months before.

[Note well: This isn't typical stuff for us. If it was, I don't know that we'd be able to enjoy it. It was sort of a second honeymoon, and we had a great time. I guess I'm saying this because, where I come from, you'd get embarrassed if people thought you were running around attending shows in Manhattan all the time. Gordon Lightfoot speaks for me: "Sometimes I think it's a shame when I get feelin better when I'm feelin no pain"].

Anyway, on to Item 3. A lecture-series ad in today's New York Times includes this note about sold-out events: "A limited number of tickets may be available at the box office one hour before curtain."

Now, WHAT IS THIS ALL ABOUT? Do theaters in New York (and other places) hold back a few choice tickets to sell at the last minute? If so, why? It's mainly just a curiosity for me. But, yes, there's the very practical side too. I'd appreciate hearing from anyone with similar experiences, and especially from whoever knows the inside scoop.