I think this recording is justly described here (Editorial Review from amazon.com):
"Deutsche Grammophon 028945942421; 2 CD's; Fritz Wunderlich is in absolutely stunning voice in this classic recording of Mozart's "Turkish" opera brilliantly led by Eugen Jochum. Kurt Bohme is a lively, rich voiced Osmin, while Erika Koth and Lotte Schadle are a vivacious pair of female leads. Friedrich Lenz makes for an expert, lyrical second tenor! "The Rough Guide To Opera" says that "this is a justifiably famous performance, . . . not least for its being the first of the opera to present the score uncut. It is also celebrated for being one of Fritz Wunderlich's last and finest studio recordings. There is no portrayal of the role on record so in keeping with its luxuriant musicality, and even if one might find his performance sentimental, this is a small price to pay for singing of such extraordinary beauty. The rest of the cast produce first-rate performances, with a lively, characterful Constanze from Erika Koth and a witty, energetic Blonde from Lotte Schadle. Kurt Bohme is suitably imposing as Osmin, and every bit the axis of the drama. Jochum concentrates on his cast after the traditions of his youth. . . . A treasure from start to finish, beautifully recorded."
I agree with this. Wunderlich sings superlatively, the rest of the cast is really good (the women are better than those on the DG-Böhm version, which is a recording to be avoided due to the almost ugly sounding singing voice of Schreier as Belmonte). The conducting could be a bit sharper by Jochum at times but overall he does a very good job. The sound quality of the recording is really good.
Instead of buying the complete 2 CD set, I bought the highlights disc for the princely sum of 1p for one reason only: in my quest for the best recording of this splendid showpiece opera, I knew, having heard the whole thing, that even if it wasn't the favourite overall, I had to have Fritz Wunderlich singing Belmonte, as no other singer in recorded history is so accomplished, impassioned or beautiful of voice in that role; hence I broke my normal habit of avoiding highlights discs just to ensure I had all of Belmonte's big moments - including, of course, "Ich baue ganz".
Certainly none of the other singers in the cast is necessarily better than, or even as good as others in alternative sets: Kurt Böhme as Osmin is nowhere near as steady, resonant or agile as Moll or Frick and he tends to bark and growl. Erika Köth as Kostanze is sweet and accurate but somewhat shrill, tremulous and tweety, even if one admires how neatly she negotiates the coloratura. Lotte Schädle is vocally very similar; agile and true but bringing more than a touch of the screeches to the high-flying passages. Casting the two female roles has usually proved tricky and no-one is ideal; Arleen Augér for Böhm is the best Kostanze I've heard but unfortunately, I cannot abide Peter Schreier as Belmonte; Studer is pretty good for Bruno Weil, too. Good in the latter as Blonde is the Polish soprano Elzbieta Szmytka, as is Rita Streich for Fricsay, but one is always picking and choosing amongst various sets rather than proclaiming, "This is it". (In many ways, Callas provides the most interesting and thrilling "Martern aller Arten".) The Pedrillo is little more than adequate.
I have never been much of a Jochum fan but find no fault with his swift, nervy direction here; everything is as it should be and of course the reduced Bavarian State Orchestra is great: light and astringent with no undue thickness of sound.
Essentially this is primarily Wunderlich's show; for the complete set I would plump for Fricsay or Davis, with Weil in reserve, according to taste.
This two cd set delivers a fresh and colourful interpretation of Mozart's sing-spiel. The subject, as many of you may know, is not that serious, but at moments it has the strength necessary to become intriguing, particularly due to the excellent orechestra direction and to the incredible skills of the singers. Fritz Wunderlich amongst all, ofcourse, is the one that shines the most: his voice really suites perfectly the role, gets deep through the arias showing, appart from their glittering and perfect lightness, all the passion and the love which is profoundly concerned. The female singers too do a very good job - sometimes the almost unsingable sovracuti take them to risky moments, but as a whole they do it in an almost perfect way, sounding young and ironic, provoking and tender, lovely and free. The baritono does the best in his half comic role of the old and severe, who gets what he deserves in the end, with moments of absolute fun here and there. The only problem with this could be the moments of speech between one aria and the other: the carachters sometimes go a bit beyond our standards of acting and sound a bit excessive tending to become rather more masks of 18th century theatre than actual characters. They reminded me of the use of masks in Goldoni's commedias somehow. As a whole, a great album. Worth the money.