It´s completely absurd ! It reflects a little bit her attitude towards recordings. Guys like Zimerman and Pogorelich haven´t produced a solo CD since almost 10 years (Zimerman: 1995, Pogorelich: 1996) which is also a little bit strange but it is due to their high self defined standards. Idil Biret just opens a score and records it. She didn´t realized that the 51 exercises a not precisely the same as let´s say the Intermezzi ! Funny.