Mozart raised the status of the piano concerto to a new level with his glorious cycle of 27 works. But Beethoven raised the stakes yet again. The first two concertos are closer to the Mozartian model; the Third is a wonderful work with some incredibly imaginative touches. With the Fourth and Fifth Piano Concertos (No. 5 is the "Emperor"), Beethoven created two masterpieces. With No. 4, he pits the soloist against the orchestra (unusually for the time, the piano starts the work alone) and in the second movement, the intensity of that head-on collision is very powerful. The "Emperor" is a much grander affair with the soloist very much centre stage, but again the slow movement is a thing of wonder — tender and seemingly timeless. Wilhelm Kempff and Paul van Kempen, regular partners, perform with poetry and authority.