It’s about sixteen months since instrumental Montreal collective Godspeed You! Black Emperor last played Ireland, and with the venue, stage backdrop, equipment, lighting, and setlists almost identical to the last, there’s a familiar sense of n different sort of ritual on this particular Sunday at Vicar Street. The ongoing sub-50Hz rumble of the venue gives way to the entry of the seemingly accidental wandering onstage of a percussionist, double bassist and violinist, kept just visible by warm amber light. As they ease into some droning, exploratory notes, more musicians appear onstage, before the mass organically transforms into the band’s now…