The Tate Gallery at Liverpool has an exhibition on at the moment consisting of art chosen by Marianne Faithfull. It was all chosen because it was meaningful to her in some way, and the collection was a fascinating mixture of artists, media and styles. One of my favourites was this little sculpture by Yoko Ono – a cluster of pyramidal prisms with a light shining through from underneath. It produced a wonderful pattern of refracted light on the studio walls, but unfortunately the effect didn’t come out at all well in my photos – the close-ups you see here worked a whole lot better. They remind me of the crystals on the inside of a geode.