Define a lot. Some musicians have a more experimental (or rather, interpretative) approach than others for sure, but I'd say conventionally the differences aren't great. I don't know enough about classical music to give a very detailed answer though

Also actually, I think the analogy with spoken language applies here too: I think the differences between classical music performances are comparable to different actors playing the same role in a play, although plays leave a bit more room for variation maybe

It’s an apt analogy imo

A play might even leave less room for interpretation depending on factors like the personality of the theatre director and how much instruction the composer included with their scores and so on.

Plus, that ability to find that really perfect tone which is universally crucial throughout all genres of music from garage rock guitar hooks to free jazz saxophone to classical even to computer generated drone ... it’s completely make or break and there’s no faking it.

All of that is spot on. To me it's all about the group's sound. Of course, they need to be good musicians in their own right but a group of talented people don't always add up to a crack ensemble. That magic is rare. And it doesn't always communicate despite what the players may be feeling (as anyone who's ever played in a band could tell you!).

I like the early Juilliard Quartet's version because they were in a period where Happy Birthday would have sounded fabulous. They just had that indefinable fire and cohesion missing from most versions of the quartets that I've heard. I'm listening again to the Danish Quartet's version of Op. 131 (in the first post) and, for me, while there are moments of brilliance (particularly in the up-tempo movements; the scherzo, in particular) they lack the power of the unity of voices in the Juilliard version. They play beautifully but, to me, the Juilliard group were on another level. But, as they say, to each his own.

I think part of that is being such a good musician that you can not only play your part but you can simultaneously play in your head the other parts and as a result they know exactly where to show deference make a little space or even attack harder to harmonize and there’s even little cues in the playing that communicate pick it up here or sweep in like this or here we go to climax or interlude.

And you know they practice together all the time and know how to communicate verbally. But I don’t think it’s just that. Like I’m saying above there’s something borderline telepathic about it.

Much much easier for me to spot in jazz though.

Thought I’d move to a more bite-sized quartet and picked No 11 Opus 95 in F Minor, “serioso”. Man, do I pick em. Opus 95 backstory.

And, well yeah, the Alban Berg Quartet again. :D

:) Dave Hurwitz calls The Alban Berg the Viennese clone of the Juilliard Quartet. His videos are fun to watch (if you’re really interested in classical works). Here’s a run-down of his favorite Beethoven String Quartet cycles on CD:

Good, full-bodied, spirited version of the "serioso" quartet.

This is a good "interpretation" of the Serioso, particularly of the 1st movement and Beethoven's approach to music, in general:

Beethoven's Concerto Grosso is my favorite work from him, his 15th and 16th Quartets are also him in his prime, truly innovative stuff as well