The first band on the list of bands that appears at some public music performance of some kind gets the sales from the first 20 tickets, then the next band gets the next 20, and so on.
在列表中的第一个乐队， 在某种公众表演中 销售了第一个 20 张演出票， 第二个乐队卖掉下一个 20 张， 以此类推。