Sun & Moon is an ad-hoc percussion ensemble started by Per Nørgård and Ivan Hansen at the beginning of the 1980s. It appears at intervals – for Nørgård performances like this one, at open courses at music colleges and high schools, and in more concentrated courses at music academies and the like. The group gathers when Nørgård’s “infinity rhythms” have to be played, which, as in this case, consist of light + dark and dark + light beats in a multitude of fractal patterns based on Nørgård’s special “infinity series”. Sol & Måne is thus the name of en ensemble, but has gradually also become the name of a particular Nørgård genre. A central feature is that everyone – young/old, amateurs/virtuosi (at the level and tempo they happen to master at the time) – can form part of a rhythmic ensemble, and on an equal footing. This was the case in the first performance of Nørgård’s work in Birmingham in the spring 2005, where twelve English music-school percussionists and Ivan Hansen were the drumming friends of the will-o’-the-wisp children. Sol & Måne consists of six experienced Danish Nørgård percussionists: David Hildebrandt, Mathias Reumert, Fredrik Olsen, Linda Edsjö, Anton Davidsen and Ivan Hansen.