This Ain't Free!

Sunday evening, heading down the stairs for a Brooklyn-bound F-train at West 4th. As I was descending, I heard some pretty impressive drumming, and when I got to the platform, I saw a man who had set up a full drum battery and was going crazy on it. He was great. Two tourists stopped in front of him, and one of them whipped out his iPhone to make a video. A few seconds later, the drummer noticed the man recording him and immediately stopped playing. "What are you doing?" he asked. The tourist looked surprised, but kept on filming. The drummer pointed to a plastic cup on the floor with one of his sticks. "This ain't free!" he said. "You want a show, you pay for a show! I ain't gonna let you film me without a donation."
"You want money?" responded the tourist, taken aback. "I don't have any money. I just wanted a souvenir."
The drummer stood up. "You want a souvenir, you pay for a souvenir. You put money in that cup, you get your souvenir."
As I walked down the platform, I could hear them squabbling behind me. All of a sudden, the arguing stopped, and the drumming resumed. I can only surmise that the tourist had either paid the drummer in bills or left the platform in shame, since I never heard the clink of coins.