richter is indeed an excellent interpreter of beethoven sonatas. i don't have any recording of him playing no.4, though (i only have it from brendel and kempff, i think). his rendition of no.12 "funeral march" is very good, perhaps the best performance of that sonata that i have heard. i also liked his recording of the first piano concerto. i wish i brought it with me to istanbul, i could just pop into the cd player in right now.