The Completion Problem
In a footnote to history, Henry Kissinger was to have written a piece called "The Collaboration Problem," outlining his thoughts on accepting a Nixon appointment. He never did, as he decided he would rather have the job with Nixon than have his morals intact. In any event, the problem of completions of works like Mahler's 10th is similar to Kissinger's problem.
Can you make things better by working from the inside? Can you complete something fundamentally impossible to complete?
Mahler completed the Adagio and Purgatorio to the 10th, with some portion of the first Scherzo. The entire symphony, though, is written out in four stave notation. That blueprint allowed Deryck Cooke to go back and make a "performing version" of the work. That "version" was revised a couple of times - and conductors frequently add or subtract bits as it suits them (Simon Rattle being first and foremost among the offenders). However, my problem isn't a textual issue - it's a conceptual issue.
Should we complete Mahler's work? The man was a genius with few comparisons (Bach and Wagner, maybe), and he was an orchestrator without equal (saving, perhaps, Wagner). Fate snatched him out of the musical world before he could apply his genius to what looks to have been his most revolutionary symphony. Just listen to the brass chorale in the Adagio: it is a cry from the depths, pierced by a trumpet, like a stab through the heart of the symphony. Is it Alma's dalliance with Gropius finding voice? Mahler's - by then, obvious - looming death? Who knows? Who, more to the point, wants to know?
That, I suppose, is my attitude about the completions in general. Play the Adagio, play the Purgatorio - and leave the rest where it is. The problem of completion is this, and only this: where does one draw the line? Does the nervous and tragic second Scherzo need a voice? Assuredly. Is there anyone other than Mahler who could reasonably give it a voice? Likely not.
That is why the 10th is infinitely more tragic than the symphony of Mahler's most commonly afflicted with the title (the 6th): the content is heart-rending, but the unfulfilled promise is even more so.