My previous post, which mentioned Willem Mengelberg's 1939 Mahler 4th with the Concertgebouw, has got me thinking about the issue of the authenticity of Mengelberg's Mahler. By that, of course, I mean: How close is Mengelberg's Mahler to Mahler's Mahler? The Pristine Classical site notes,
A more reflective and incisive analysis of the situation comes from Tony Duggan,Secondly we have to look to the performance, as this is one which is simply unique. [Mengelberg] had been a close friend and associate of Mahler's; he had been present at the premiere of this symphony; the two conductors (for conducting was for what Mahler was chiefly known during his lifetime) worked on the score together, adding timing marks, annotations and fine detailed notes throughout.
Mengelberg sat in the audience in Amsterdam in 1904 to hear Mahler conduct the symphony with the Concertgebouw Orchestra twice in the same concert. He also attended the rehearsals, discussed the work with Mahler, and made copious notes in his score with Mahler's co-operation. Mahler in turn had a very high opinion of Mengelberg's conducting of his music so any recording by the Dutchman must carry a degree of authenticity but with the caveats that need to be applied to that word in this context. Whether what we hear in the "live" concert recording from November 1939 [...] can be said to represent Mahler's own wishes is another question. I would only point out that by this time twenty-eight years had passed since Mahler's death and Mengelberg, a conductor known for a very expressive style, must have developed his interpretation in those years however much it may have been influenced by Mahler to start with. However, I think we can say this recording gives us a window into the way the generation nearest to the composer saw and performed his works.
The problem is, as I noted, comparing Mahler's 1905 piano rolls to Mengelberg's 1939 performance of the 4th is like comparing apples to oranges, speaking in a substantive sense. Mahler performing at the piano solo is going to do things differently than Mengelberg leading an orchestra, but there are approaches to the same material that are going to remain roughly constant, regardless of media. That's where the piano rolls (and another source, to be touched upon anon) come in handy. We see that Mahler had a very fluid, very variable approach to his music. Fast, slow, relaxed, and tense seem to flow together in sequence, if not always in congruity; Mengelberg seems to have a similar orchestral concept. It seems as though he is constantly adjusting, nudging the orchestra in different directions as the performance progresses.
Another key piece of evidence is the "Remembering Mahler" oral history piece, containing interviews with people who played under Mahler. One former player notes, with palpable excitement, "Flexibility, that's what Mahler had. There must be a certain liberty in the tempo [...] No matter where it is and what it is, it is what the composer demands, not what the composer, what his composition demands." [Transcription mine] So, then, this sort of variation, bar-by-bar, phrase-by-phrase, was an integral part of Mahler's approach - at least as far as we can tell from anecdotal and limited recorded evidence. Mengelberg seems to have had the same idea, and we know that Mahler and Mengelberg were reasonably close (indeed, there seems to have been a lot of cooperation and collaboration on the 4th).
So, then, what does this mean?
Ultimately? Not much. By the time we get Mengelberg's Mahler 4th (1939), the composer had been dead for 28 years. It would be a prodigious feat of memory indeed if, 28 years after the death of the composer (and 35 years after Mahler's performance of the 4th in Amsterdam, when the younger conductor did his work with the composer on the symphony), Mengelberg could remember Mahler's interpretation well enough to affect a reasonable facsimile of Mahler's performance. I think that's suspending disbelief a little too much.
So, then, what gives? Well, I think it's relatively simple: conductors before the advent of a certain one of whose centennial we're currently in the throes modulated tempi and dynamics to fit the music. Look at Mengelberg, look at Furtwängler, and look at the rest of the Mitteleuropa-trained composers in the past one hundred years. They all knew how to do it. Mengelberg's Mahler sounds rather like Mahler's Mahler because they came out of the same musical tradition. Does Mengelberg's approach reflect Mahler's precisely at the time of the Amsterdam premiere of the 4th? Of course not. Memory and approach changes over time: Look at Solti's Decca Ring and his 1985 Bayreuth Ring. They have some similarities, but there are some key changes. The tradition leaves an imprint, regardless of changing taste (and Mahler's approach, by his own account, changed day-to-day based on mood and taste), and that imprint is where the similarities appear.
It's ultimately an academic question, but - more than that - it's a testament to what has been lost in conducting over the last fifty or so years.