So what's the answer??
Nobody seemed to know!
Not to put too fine a point on it, but Ross is selling us a piece of bullshit here. On the one hand, unless a poll were taken of everyone in who happened to be in that railway carriage and overheard Mahler's question, the only somebodies literally present who could have replied were Alma, and Rosegger, assuming that Mahler's question was sincere. That they didn't have an answer means ... what?? On the other hand, that last sentence really exists to create the expectation that Ross himself has or will eventually come up with the answer. To the degree that he does, it seems to be Thomas Ades, John Adams, and Osvaldo Golijov.
Hold on. Ross's answer to the question 'Does the poet mean the voice of the people at the present time or over time?' is 'Thomas Ades, John Adams, and Osvaldo Golijov'? Can you give me a semantic bridge to cross here?
Well, there was that one guy on Amazon whose one-star reviews of Schoenberg (early or late) likened the whole equality-of-the-tones thing to communism.