I've been to a lot of concerts where fine-art music was performed. I have noticed, and heard critics and lecturers remark, that in many performances today, the repeat signs in orchestral scores are customarily disregarded. Here are some reasons I think this is a bad idea, and why the repeat signs should be restored and cherished.
When you're listening to music, this truth is even more true because music is an art form that alters time itself. In a sense, what you are contemplating as you hear a fine piece of music is the time you are spending listening to it. That moment can never be perfectly recalled, even by a high-definition recording. In fact, your fallible memory of your impression of a live performance is probably truer than a reproduction of that performance in fully digital surround sound. A very similar moment can be created, but something definite (though hard to express in words) is lost by virtue of that very similarity. Having the ability to play back a recording may seem to obviate the need to observe repeat signs because you can always go back and hear the piece again, and even skip back to an earlier passage in the piece during your playback. But this is too much like collecting glossy prints of a great painting and pouring over magnified sections of the painting with a jeweler's loupe. It isn't so much like looking at the whole picture, considering the whole and the parts, and taking time to really look at it.
Hearing the piece with the repeat signs observed gives you a better appreciation for the structure and proportions intended by the creator. It is tempting to borrow metaphors from painting, sculpture, and architecture at this point. When the piece reaches a significant middle point and goes back to the beginning, it claims that much more time for the material already presented. It adds that much more length to the overall piece. It professes the composer's faith that his musical argument merits being heard again, being prolonged, filling a larger canvas. And it lends a weight or dimension to that section of the piece that will balance in a characteristic way against the remainder of the whole. In more specifically musical terms, observing the repeat sign draws attention to the structural identity of that first part (or a later section, if that is repeated), gives the listener a second chance to appreciate the themes as originally presented (for they may never be heard that way again), and dabbles in the waters of double entendre.
I raise this last point because the tonal relationship between the end of the first section and the beginning of the piece is not the same as its relationship to the next passage after the repeat sign. The cadence at the end of the thematic exposition (to use sonata form as an example) is thus shown in two different lights, first heading back to the home key and then, at the end of the second time through, leading off into fresh territory. Some of the great composers' most masterful strokes are at this crucial point in the musical form. They may go by unnoticed. But I, for one, have always felt my attention drawn to them.
Sometimes skipping the repeat signs means the concert hall can get more bang for its buck. It can fit more pieces of music into an evening's program, or get through larger works faster so all the unionized labor can close the shop and go home on time. It certainly doesn't make the pieces any harder to sit through, from the point of view of an audience conditioned to have a shorter attention span than that of earlier generations. But the trade-off is that they don't get to spend the time with the musical picture that they really need to take it in; they don't get to experience the mathematical harmony of its originally intended proportions; they don't get to appreciate fully the distinctness of the piece's musical structure and the way key elements in that structure have been designed to serve more than one purpose.
These considerations should carry more rather than less weight at a time of life when one has heard some pieces played many times by many different performers, because each performance is like the light of a different season or time of day shining into a differently dimensioned and decorated room. Just as the painting would look different, so the symphony would sound different in a different hall, played by a different orchestra, conducted by a different maestro, and perhaps played out of a different edition of the score. An original-performance-practice recording is going to sound quite different from a modern-instruments orchestra performance. An amateur, town-gown philharmonic society's reading of the piece, after rehearsing it one night a week for a whole quarter, is going to sound different from a world-class, full-time, professional outfit. A veteran conductor is going to lead a performance a world away from the brash young turk still struggling for his big break. A conductor who programs a lot of contemporary music may play Handel from a Stravinskian perspective, while a conductor who specializes in reviving Handel operas may play Stravinsky with a surprisingly light touch. And you'll hear them differently depending on whether you've just come away from a linen-tablecloth restaurant where you had too much to eat and drink, or whether you've come straight from work without even changing clothes; whether you're coming off a dry spell and haven't heard a concert in months, or whether you've heard every performance in the last month. In any of these scenarios, the chances are good that you will hear something you didn't expect, and may not quite believe really happened the first time. Your familiarity with the piece is part of the background against which you are aurally viewing it tonight. You may want a second glimpse just to be sure of what you saw.
But finally, I think the practice of skipping repeat signs shows a want of love and respect for the masters and their masterpieces, which true lovers of the art form ought to enjoy for its own sake and without any hurry for it to be over. The silence comes too soon. And until it comes, life is too full of unbeautiful noise and cheap, inferior music. The more of our time that we can adorn with something true and human and good, the better the world will be.