This is not a classic performance. This is the greatest performance ever recorded of the Ressurrection Symphony. Yep, the sound quality is awful, taken from a recording of a radio broadcast, but that's not the point. The point is that Klemperer, the orchestra, and Ferrier are all in top form, and that is something out of this world.
Most critics stress Ferrier's superb contribution as the high point, but I prefer the first movement. The name Mahler gave the first movement of the symphony translates "as the passage of the dead", usually said as "the march of the dead" as it is in march tempo. A reviewer of the original performance described as 'you could see the shrouded dead marching down the fog bound deserted streets of the city.' Last time I counted, I had 15 recordings of this symphony, and there is nothing like Otto's first movement.
You really need two recording s of this work, a good modern digital one (Chailly on Decca or Boulez on DGG or Tilson-Thomas on SFO) to here how it sounds, and this one by Otto to hear how it ought to be done.
Back to sound quality, the lp from 25-30 years ago is smoother, definitely preferable to the transfer to CD, but good luck finding a copy.