ska strumming is kindof a technique, kindof a rythym, and kindof just an emotion when strumming the strings. usually ska strumming is on the upbeat, keeping a faster pace than reggae. it takes a little practice to get it good, i started and hardley knew what the **** i was doing, i used to be way into ska punk and stuff, so thats the first stuff i learned. with practice your strums will sound just like catch 22. saw them at a local venue, BTW. they kicked major ass.