Although being a disciple of Mahler as Bruno Walter, Klemperer was a musical conception quite opposite to that of his colleague as Bruno Walter emphasizes the feeling, the dance when the music alludes, charm, pulling sharply to the Mahler romantic past, as Klemperer pointedly refused these and the eventual picturesque, anything that can make attractive Mahler first degree, highlighting its modernity. We recognize the historical situation of Gustav Mahler at the junction of two musical eras and with it the danger of taking away too assertive: it's probably because of the refusal of any scenic element and decorative than the first two movements of the Fourth Symphony are deprived of their content by Klemperer, becoming a music which one can enjoy the atmosphere highly hypnotic, light and architecture, but all the details are erased.
This illustrates the Fourth Symphony "marmoreal" adjective that is associated with Klemperer, which is linked to a musical conception, but is also the result of age and the head of state of health, something fixed in seeming music in relation to the partial paralysis of his face. That is why we must be careful not to neglect the oldest recordings of Otto Klemperer, much more "alive" and animated in a fast tempo: eg, you can compare the "Resurrection" Mahler: Symphony No 2 in this case with that of 1951. A priori, one would think that in these recordings installments between 1961 and 1968, the most recent are the least commendable, but it is not verified by listening, the old chief preserving its qualities of construction, including a 7th the slow extreme and quite destabilizing, but beside it is not irrelevant and may even passionate.
It is not without disadvantage of not knowing the 7th that in this version, but those with few disks may consider that the second and especially the Song of the Earth remain references (absolute reference for the second according to some commentators) 9th remaining to a lesser extent one of the most important recordings. On the one displayed austerity, she refuses the charm contained in the third and especially the second movement also seems to deny the desperation of the first by a sort of voluntarism; yet it is a marvel of construction and its great merit is its enhancement stamps. For the Fourth and Lieder sung by Christa Ludwig, I refer to my comment Mahler: Symphony No. 4-5 Lieder; the same for the 2nd Mahler: Symphony No. 2 'Resurrection' and Mahler's Song of the Earth: The Song of the Earth.