We had an event in the RA Schools in which Usher, an American R&B star, talked to a large group about his experiences in life.   He was surprisingly soft spoken, deeply thoughtful, with the intonations of the church choir.   He came to the RA first for the Hockney exhibition, then for the Summer Exhibition (which he sees as providing unique opportunities for emerging artists), now supporting our learning programmes, interested in art and influencing the young for good.   Emotion, illusion, delusion, these were his descriptions of the experience of art.