First 3 chords of Les Adieux

[wwalrus]

Is there a nickname for these three chords (besides Lebewohl)? I've seen it used so much in various compositions. Brahms 2nd concerto, handel variations, and so many others. Is there any background info as to why these intervals seem to appear so much?

[piulento]

Really interesting question. I've been thinking about this too lately.
I don't really have an answer, just joining the thread to get one too 

[lostinidlewonder]

Check here:

https://www.mtosmt.org/issues/mto.96.2.4/mto.96.2.4.agmon.html

The Meaning of the Interrupted Lebewohl-Motto

[5] Any representational interpretation of Op. 81a may well begin with the disruption, both textural and harmonic, that the left-hand’s entry in measure 2 inflicts upon the right-hand’s Lebewohl-entity initiated one measure earlier (Example 1). Leonard Meyer believes that “this [deceptive] cadence further defines the ethos of the motto, bringing ‘the eternal note of sadness in’ and perhaps suggesting that the parting is not final.”(9) Indeed, as Meyer subsequently points out, Beethoven’s placing of the horn figure at the beginning of the composition rather than the end, where it more typically belongs, is already deviant.(10) However, I believe there is more to the left- hand’s interference with finality than Meyer suggests.

[6] Several commentators have suggested a possible connection between Beethoven’s Op. 81a and Bach’s “Capriccio on the Departure of His Beloved Brother” (BWV 992), apparently composed when Bach was only nineteen years old on the occasion of his brother Johann Jacob’s departure to join the retinue of the King of Sweden.(11) Kenneth Drake’s observations are most illuminating in this regard. Noting that Bach conceived his first movement as depicting the attempts of the brother’s friends to deter him from embarking on his journey,(12) Drake presents examples from both Bach and Beethoven where “. . . melodic continuity and harmonic movement are held back, display vacillation, and are postponed . . .”(13) Surely, though, the quintessence of held- back harmonic movement in Beethoven is the deceptive cadence of measure 2, which Drake fails to cite. It thus appears that Beethoven’s movement is not so much a depiction of the sorrow of parting, as is commonly assumed; rather, like Bach’s, the movement depicts (or at least begins by depicting) an instinctive reaction of any human being to a projected departure of someone he or she deeply cares for: preventing that someone from executing the pain- afflicting plan. This, I believe, is the meaning of the left-hand’s interference with finality in measure 2, signified (as Meyer and others have rightfully observed) by the right-hand’s Lebewohl-motto.

[7] In light of Bach’s capriccio, in other words, the first movement of Op. 81a may be interpreted as depicting an external struggle, namely, Beethoven’s struggle against Rudolph’s intended departure. As in the fourth movement of Bach’s work, where the friends realize that the brother’s departure is inevitable and bid farewell, by the end of Beethoven’s movement the struggle against Rudolph’s projected departure subsides, and leave-taking takes place. However, I believe that even greater insight into Beethoven’s work may be gained by applying a variant of the same idea. According to this variant, which I shall pursue through the remainder of this essay, the struggle depicted in the first movement is internal: Beethoven’s subconscious denies what his conscious self already knows, namely, that the Archduke’s departure is imminent. This idea of an inner struggle, however, is more properly introduced through a brief psychological digression.(14)

[wwalrus]

What a fascinating take on the sonata. So why does this seem to appear so much outside of 81a?

[pianoplayer002]

In some languages this progression is called something along the lines of a "horn fifth", which in E flat major would be Eb-G (third) Bb-F (fifth) G-Eb (sixth), just like the start of Les Adieux, except in Les Adieux it's harmonized as a deceptive cadance instead of a normal one, which is bound to have been a real surprise for contemporary audiences.

I believe the significance of the motif is that it's something that typically a brass section would play, and it's often used as a "hunt" motif, or as a fanfare. It most often appears in Viennese Classical era music (Mozart, Beethoven, Haydn etc), because I'd assume this type of motif would be more associated with the elegance of the courts employing the composers of that time rather than with the individuality and swirling emotion of the romantics.

[kalirren]

As pianoplayer002 said, it's a horn progression.

The piece is inspired by Beethoven's friend's sudden need to leave town because of Napoleon's army invading, so that horn progression is symbolic of a distant, invading army bringing bad news.

The opening horn progression is contrasted against the more fanfare-y motif in the fast section, (you know, the one that goes, "baah, ba-ba-bum, ba-ba-bum, ba-ba-bum") but you should think of it as the same brass band playing a different, more pressing tune.

[dcstudio]

I think you are looking for a deep meaning in a very simple progression.  It's a deceptive cadence that follows the simple rules of part writing and good voice leading. I don't mean to suggest that there is no emotional connection..
My edition has lebewohl written right above the chords as if for a chorus. It meant something to Beethoven no doubt.
As to why it appears so much in other works is hard to say without studying more than I care to right now.  If I were to make an educated guess I would say that in Beethoven's time this motif would have sounded familiar to audiences. This was before Berlioz and the idee fixe, and Wagner's leit motif but this doesn't mean that there weren't familiar tunes and progressions that reminded people of certain things...like hearing Taps being played by a single horn reminds us of the military...or military funerals. As it has already been suggested...it's meant to sound like a horn fanfare.

I know of no nickname for this particular progression but there may have been one in Beethoven's day. 

[pianinha]

As to why it appears so much in other works is hard to say without studying more than I care to right now.  If I were to make an educated guess I would say that in Beethoven's time this motif would have sounded familiar to audiences. This was before Berlioz and the idee fixe, and Wagner's leit motif but this doesn't mean that there weren't familiar tunes and progressions that reminded people of certain things...like hearing Taps being played by a single horn reminds us of the military...or military funerals. As it has already been suggested...it's meant to sound like a horn fanfare.

I know of no nickname for this particular progression but there may have been one in Beethoven's day. 

Maybe a napoleonic army theme or any other army theme, now lost for sure. You raised a valid point.