Trumpet player on the Metro, what was in the sandwich?

You sat on the Metro early on Monday with a trumpet case across your knees and a sandwich the length of your forearm, and you ate it slowly, with total focus, like a person at a concert. I was standing beside you holding a plant. We looked at each other once. It was a look of deep mutual respect. You got off at Insurgentes still chewing. I would like to know what was in the sandwich. I would also like to know how you play the trumpet with a mouth that full.