Godspeed to your dad Jim.
My dad took me on one of his business trips to Cleveland and Detroit when I was in junior high (I think). Anyway, he gets us tickets to Indians and Tigers games. Nice box seats. I noticed that my dad gives the usher our tickets, the usher wipes down the seats, and my dad "slips" the usher a couple of bucks. I didn't say anything - just noticed. And I noticed other men, relative same age or older doing the same thing. Later on I realize that he / they were tipping the usher for wiping down the seats. Now when I get seats at my local AAA ballpark, Huntington Park, or other stadium where the usher wipes down your seat I make sure that I have a few bills available for the ushers. I also observe others in my age range to younger that haven't a clue.