To use a specific example, the fourth movement of Beethoven’s fifth is marked Allegro. My music dictionary defines Allegro as, “lively, brisk, rapid,” but how lively, how brisk? Is my brisk walk the same as your brisk walk? These are decisions made by the conductor.
(Some composers - including Beethoven in certain instances - will specify the precise tempo through the use of a metronome. But conductors often don’t follow these precise instructions.)
Conducting is more than tempo and rhythm (not saying you are saying it, of course, just trying to amplify), differences in dynamics (forte/piano) changes in dynamics, how much each section is heard (violins, cellos, winds, brass, …) at any one time and when changes in which section is more salient, … There are hundreds of decisions that can affect the outcome. And then, there are the size of the orchestra, the instruments on which each player plays and maximizing the potential of the instruments, … It would be fun to make a list of all the potential factors affecting how the score is heard.
The composer writes the score but that is really just a skeleton on which the music is built. Tempo, balance between orchestral sections, expression and an host of other things all make a difference. With streaming services you can listen to different conductors’ interpretations of the same piece and hear perhaps how one version really moves you, whilst another leaves you cold.
With some 20th and 21st composers, there are recordings conducted by the conductor themself and it can be instructive to compare with other interpretations.
Go to as many live concerts as you can. Sitting in the audience for an orchestral performance can emotionally engage you in a way no HiFi, however good, can quite do.
Roger
100% 
Hi @jegreenwood
Thank you for the information.
What are “Koechel numbers” ?
What does BWV stand for?
I’m not a musicologist, but one of the first composers for whom we frequently see Opus numbers (or at least for some works) was Haydn, roughly a contemporary of Mozart.
Ludwig Ritter von Köchel was an Austrian musicologist who catalogued Mozart’s works. As such, Mozart’s pieces are usually identified by a “K” or “KV” plus a number (denoting Köchel-Verzeichnis”) which references the order in which a piece appears in the catalogue.
Same idea with BWV, but that refers to the “Bach-Werke-Verzeichnis” of J.S. Bach’s works compiled by Wolfgang Schmieder. Sometimes (rarely, in my experience) you will see this as an “S”, indicating “Schmieder”, but the numbers are the same.
The KV numbers attempt to be chronological. The BWV numbers are grouped by genre, starting with the Bach cantatas.
Other composers whose works have been catalogued in this way include Haydn (Hoboken), Schubert (Deutsch) and Beethoven (Kinsky-Halm, Hess, identified by WoO, although you also see his works listed just by Opus number a lot of the time).
Edit: Sorry, I was writing this just as the previous post was being added!
Hi @jegreenwood
Thank for this.
I have now disappeared down a rabbit hole 
.
They must have all had a lot of time on their hands.
Lots of familiar material here from Fanfare for the Common Man to the old American songs. Always interesting to hear the composer conduct.
Agreed, and I have enjoyed listening to that recording many times, although in the case of Copland I would say that Bernstein understood Copland’s music as well as the composer and conducted it better! They were practically lifelong friends, and of course there were rumors (unsubstantiated, but believable) that they may have been romantically involved early in Bernstein’s life. There is no doubt they loved one another as friends and colleagues, and that Bernstein dearly loved Copland’s music and tried to give it his all.
And I will add that the fall of 1990 was a bad season for a 14-year-old who idolized Bernstein and loved Copland’s music!
Almost as much time as I’ve spent tagging the collection on my server.
Thanks for that Coleridge recommendation. A beautifully intimate requiem.
Oh wow. Your message made my already pretty good day. 
He’ll conduct it at Coventry Cathedral on May 10th as part of a Come&Sing, by the way.
Not a lot, except that it makes it easier to track down a piece of music later if you want to listen to it or buy your own copy. Less relevant in the internet age but, as a teenager around 1990, I found it invaluable to know that the delightful piece of piano music I heard twice separately on R3 was Schubert’s D959 so I could buy a copy. Still love it.
I’m fairly musically trained (to the point where I’ve written and arranged music that’s been performed at public occasions, if that’s a useful measure), and I don’t get much more out of this information than that. I suppose knowing that the Köchel catalogue numbers are (intended to be) chronological means that I can gauge roughly where it falls within Mozart’s life & work.
Mark
Yeah, that disc is pretty special isn’t it @EJS ?
The 4D tech to my ears works very well. Un Barque is a highlight, but Mere L’Oye is stunning too.
A lovely DG 180g reissue. Although a bit too much noise in the pressing for my liking. Recording sounds great. I like Schneiderhan’s own Cadenzas, but these not everyone’s cup of tea, I’ve read.
The “4D” was heavily marketed at the time but the blurb made no sense whatsoever and I never quite understood whether it meant shorter analogue cables, new downsampling algorithms or something else. It didn’t always work out but this one does sound very good, indeed.
There’s a DSD download of that packaged with the Triple Concerto (with Anda and Fournier) and the Brahms Double (with Starker). Available cheap at ProStudioMasters and cheaper at Qobuz if you’re a Sublime subscriber.
As usual, I believe, but cannot prove, that this is from the master used for the Tower Japan SACDs.
