The jazz trumpeter is wearing polka-dot pyjamas and a red jacket. His hair is shaved at the sides and piled high on top with a flourish of stylish yellow. The stage is at the same level as the seated audience in waiting; and we are sitting inches away from where the musicians will perform. The drums are sleeping and there is a strangely shaped trumpet left carelessly on the floor, the very reason why the basement cavern is crowded with an audience of such diversity of age, race and background – united by a knowledge and love of jazz but including at least one musical illiterate. People have finished eating before the first set begins. There is a quiet thrill in the air, like the excitement of children who know that what they have long wanted is about to happen.There is a magic to ev