Despite being a Monday after the weekend before there’s a sense of excitement for those milling around waiting for the show to start. They’re all ages, a physical embodiment of the decades long span of Swans career and the age defying loyalty they inspire. But before that there’s something of a gatekeeper in the image of Okkyung Lee (below). Her face spookily serene, she weighs taste on her rapidly moving bow as she makes her cello gurgle, spit, shout and scream. In fact everything except sing. So is this deranged arthouse fun? There is something of the performance about it,…