We won’t rehash the history of Jazz here, which was first a great surge of outcasts before becoming a style. It is in this surge that Sidney Usher runs to seek refuge. That’s how he ended up, in order to cope with not existing, by finding, if not the vein, at least, the way to dodge everything that’s not quite right around him and which, on certain lonely evenings at that time, really makes his head spin, like a pumpkin…