Hi Goofyfoot - my first thought about your post is to say that to a musician, the fact of performance practices being handed down from teacher to student goes without saying, though I guess that is maybe not so obvious to a layman, so it is good you point it out. However, one caveat with it - you remember the elementary school exercise where the teacher whispers a sentence to one student, who in turn whispers it to the next, etc., and even if it is a relatively small number of students, the last one who speaks the sentence aloud finds that it is often completely different from what the teacher had said in the first place? This most definitely applies to this conversation.
And it's interesting that you use the Walter/Mahler example - many felt at the time that Walter did not take the same tempos as Mahler, that others interpreted his music quite a bit better (Richard Strauss, for instance, even though he didn't particularly care for Mahler's music), and I personally have never found Walter's recorded Mahler interpretations to be particularly good, either. Those were done, of course, long after Mahler's death, and even longer after the two actually worked together. Just because someone knew someone very well and worked with him does not necessarily mean that they actually do things the same way, even if they think they do. Some musicians, however, do really like Walter's recorded Mahler interpretations quite a bit.
Mahler himself was quite famous for making alterations to Beethoven's scores, to account for the increased size of string sections and the differences already occurring in the instruments themselves. Now, however, brass instruments in particular are even bigger and heavier than in Mahler's day, and there is actually starting to be a reaction against this now - many younger brass professionals are switching to smaller, lighter instruments, though they still play them much louder in general than even fifty years ago.
Another very important thing to note about the development of conductors - in the old days, they all learned in opera houses that existed in basically every German town. I think there were almost 70 opera houses in Germany in the days when Strauss, Mahler, Walter, Szell, Furtwangler and all those other guys were coming up. There were plenty of places for them to learn their trade and experiment. Young conductors today simply do not have this available to them, even in Europe. Young conductors hardly ever get to be front of an orchestra and actually practice conducting. The loss of all these different opera houses and orchestras that used to exist has had a huge effect on the training and experience a young conductor can receive now as opposed to them. This accounts for the general decline in the level of many young conductors. There are still some coming up, but in general there has been a huge decline in the number of "world class" conductors.
As to your comments on the recording industry, yes it has totally changed how music is learned and raised the standards of live performance to almost ridiculous levels. It is a very telling fact that Strauss and others who were around at the beginning of the sound recording era actually hated the idea. Recordings have really driven the quest for technical perfection in performance to ridiculous levels - kids coming out of the top music schools nowadays are absurdly good players of their instruments, even more so than when I was in school in the late 80's/early 90s. However, there has been a corresponding decline in their knowledge of other aspects of music besides the technical playing of their instrument. They can play anything, but meanwhile everyone is starting to sound more and more the same, and regional differences in sound are beginning to disappear. It is a very sad thing.
And as for the recording process itself - audiophiles do not like to hear this, but it really is true that the musicians and conductors have almost zero control anymore over that process. With the digital technology they have now, and the ability to edit pretty much anything they want however they want, recordings are almost completely "fake" now, especially if we are talking about electronically produced popular music. But even in the classical world, I have participated in recording sessions where take after take was done that sounded like dog crap. However, the extremely heavily edited final product sounds just fine, though it bears almost no resemblance to what actually happened. All commercial recording is like this now. It bears almost zero resemblance to reality. About the only recordings that are close to "real" in this sense are the live radio broadcasts that orchestras do. Though even these, unless they are truly being aired live as the performance is happening, are often chosen from all the performances of the concert in question. I happen to serve on the musician committee that helps determine what is broadcast from our classical concerts in my orchestra. It might be the overture from Saturday, the first two movements of the concerto from Sunday but the last movement from Saturday, etc. That's about as close to "live" as you can get nowadays, unless you know you are listening to an actual live broadcast. OK, I have once again posted way more than I meant too, so I'll shut up now.
And it's interesting that you use the Walter/Mahler example - many felt at the time that Walter did not take the same tempos as Mahler, that others interpreted his music quite a bit better (Richard Strauss, for instance, even though he didn't particularly care for Mahler's music), and I personally have never found Walter's recorded Mahler interpretations to be particularly good, either. Those were done, of course, long after Mahler's death, and even longer after the two actually worked together. Just because someone knew someone very well and worked with him does not necessarily mean that they actually do things the same way, even if they think they do. Some musicians, however, do really like Walter's recorded Mahler interpretations quite a bit.
Mahler himself was quite famous for making alterations to Beethoven's scores, to account for the increased size of string sections and the differences already occurring in the instruments themselves. Now, however, brass instruments in particular are even bigger and heavier than in Mahler's day, and there is actually starting to be a reaction against this now - many younger brass professionals are switching to smaller, lighter instruments, though they still play them much louder in general than even fifty years ago.
Another very important thing to note about the development of conductors - in the old days, they all learned in opera houses that existed in basically every German town. I think there were almost 70 opera houses in Germany in the days when Strauss, Mahler, Walter, Szell, Furtwangler and all those other guys were coming up. There were plenty of places for them to learn their trade and experiment. Young conductors today simply do not have this available to them, even in Europe. Young conductors hardly ever get to be front of an orchestra and actually practice conducting. The loss of all these different opera houses and orchestras that used to exist has had a huge effect on the training and experience a young conductor can receive now as opposed to them. This accounts for the general decline in the level of many young conductors. There are still some coming up, but in general there has been a huge decline in the number of "world class" conductors.
As to your comments on the recording industry, yes it has totally changed how music is learned and raised the standards of live performance to almost ridiculous levels. It is a very telling fact that Strauss and others who were around at the beginning of the sound recording era actually hated the idea. Recordings have really driven the quest for technical perfection in performance to ridiculous levels - kids coming out of the top music schools nowadays are absurdly good players of their instruments, even more so than when I was in school in the late 80's/early 90s. However, there has been a corresponding decline in their knowledge of other aspects of music besides the technical playing of their instrument. They can play anything, but meanwhile everyone is starting to sound more and more the same, and regional differences in sound are beginning to disappear. It is a very sad thing.
And as for the recording process itself - audiophiles do not like to hear this, but it really is true that the musicians and conductors have almost zero control anymore over that process. With the digital technology they have now, and the ability to edit pretty much anything they want however they want, recordings are almost completely "fake" now, especially if we are talking about electronically produced popular music. But even in the classical world, I have participated in recording sessions where take after take was done that sounded like dog crap. However, the extremely heavily edited final product sounds just fine, though it bears almost no resemblance to what actually happened. All commercial recording is like this now. It bears almost zero resemblance to reality. About the only recordings that are close to "real" in this sense are the live radio broadcasts that orchestras do. Though even these, unless they are truly being aired live as the performance is happening, are often chosen from all the performances of the concert in question. I happen to serve on the musician committee that helps determine what is broadcast from our classical concerts in my orchestra. It might be the overture from Saturday, the first two movements of the concerto from Sunday but the last movement from Saturday, etc. That's about as close to "live" as you can get nowadays, unless you know you are listening to an actual live broadcast. OK, I have once again posted way more than I meant too, so I'll shut up now.