Several people have asked about a piece of music that is sometimes playing before sessions. It is 'Spiegel im Spiegel' (the mirror in the mirror) by Arvo Part played by Tasmin Little and Martin Roscoe. It can be found on YouTube if anyone wishes to experience it. The piece lasts just over 8 minutes and you get it all (without adverts) if you select the Little /Roscoe 'Fratres' upload.
As a child I remember placing a mirror to face another mirror and wondering whether I was glimpsing infinity as I stared down the 'endless corridor' of reflection. It seemed magical. Many feel that music can be magical and can somehow grasp the infinite. Perhaps that is why Arvo Part created this simple, beautiful piece and called it 'Spiegel im Spiegel'.