This the famous 1951 Carnegie Hall Verdi Requiem recreated in "accidental stereo". For a technical explanation, I refer you to sound engineer Andrew Rose’s liner-notes. In essence what we have here has been achieved by working with two separate, simultaneously taped mono recordings independently made on microphones presumably placed in different locations. This permitted Rose to combine them to create a stereo effect. He has used the latest technology to synchronise the two recordings, remove extraneous noises, correct drop-outs and address the pitch fluctuations resulting from tape deterioration. The sound retains a high level of hiss but has far greater warmth and clarity; the blare and shatter of the mono release has been tamed and many more details emerge.
There is, however, one big caveat. Although the sound here is
much less boxy than the mono Toscanini Edition LPs, be warned:
this is not the commercial NBC version we have known and loved
for years, which benefits from RCA's later patch-up sessions and
bars snipped from rehearsals, but rather the original, unedited
live recording containing many mistakes – some really quite serious.
Pristine warn the prospective buyer of this on the cover - indicating
that this is the concert of 27 January 1951 “live at Carnegie
Hall”. On their website they inform us that the source is an “unedited
NBC broadcast recording” and "a tape made directly from the
Hall supplied by private collectors". Prospective buyers
are thus made aware of this as otherwise it might be only natural
to assume that this
is the same as the commercial recording
with which we are all so familiar.
Apart from quite a few minor glitches of ensemble and pitching there's a really obvious fortissimo bass drum entry a bar early in the first “Dies Irae”,
Di Stefano quite often indulges his tendency to run ahead of the beat, Herva Nelli attempts a false entry a bar early on “sed” (but is quickly quelled by Toscanini) and, most damning of all, temporarily falls apart completely in the "Libera Me": first she sags horrifically in pitch, then she loses her place and omits the B-flat at the close of “requiem aeternam”. Even allowing for the vagaries and vicissitudes of live performance, these are fairly major flaws, and constitute significant disadvantages in comparison with the official, mono issue, despite the sonic advantages of this stereo confection.
Nonetheless, it is possible to listen with enormous pleasure to long stretches of this most impassioned of performances. The attack of both choir and orchestra is stunning – especially the thunderous impact of the bass drum specially commissioned by Toscanini, supposedly the biggest ever made. Despite the mistakes, Nelli gives one of her most radiant and convincing impersonations of a true Verdi soprano; she employs portamento most artistically, delves into a trenchant lower register and allows her vibrant top notes to expand thrillingly; she positively soars above the ensemble. Barbieri is stern and monumental, combining beautifully with Nelli. The ever-reliable Siepi is in superb, saturnine voice, intoning his music balefully with absolute security of pitch and rhythm. Di Stefano is virile and highly expressive, and attempts the requisite tender mezza-voce in the “Hostias”, even if he cannot trill like Pavarotti. Despite the prominence of the orchestra owing to Toscanini’s preferred placement of his soloists behind them, all four singers achieve tremendous “face” and really impose themselves on the music.
So my advice is to acquire this if you want to hear this benchmark performance in unprecedentedly fine sound, but do not throw out your original Toscanini edition mono disc, as the trade-off between accepting a more error-strewn version in exchange for stereo sound might not always satisfy.
Ralph Moore
Herva Nelli (soprano), Fedora Barbieri (mezzo), Giuseppe Di Stefano
(tenor), Cesare Siepi (bass) 
