I missed “Treme” the first time around, but have lately discovered and began binge-watching it. It’s eminently binge-watchable, IMO. But I am puzzled over this bit of musician-speak that has come up every so often on the show.
So, musician dopers, what exactly does it mean to clap on the one and the three? I can guess that it has something to do with the beat and keeping time. Based on the context the line is delivered in, it is just about the worst burn one musician can give to another.