Mozart breaks....

A RULE! In composition.

http://petrucci.mus....926-moz-485.pdf

Check it out, bars 131 and 132

Top part: E B G B.

Bottom part: G B.

G, B. IN 2 voices, in similar motion, in octaves!

Just thought that was...interesting.

Heckel

Technically, no, that's not breaking the rule as the alberti pattern in the right hand presents a static movement vs. the movement occuring in the left hand. That's probably why Mozart chose the arpeggiation the way he did - to avoid breaking that ridiculous rule.

I know. but still, it's parallel octaves ;)

I know. but still, it's parallel octaves ;)

No, because when analyzing an ostinato pattern -such as alberti patterns like this- you have to think of each line being a layer. In this case, you have three layers: E, G, and B. In order for there to be a parallel octave... the B would have to move down to the E on it's next appearance. Mozart, instead, moves the B up to a C natural. Thus, there is not parallel octave. The E moves down to D#. And the G goes down to F#. Thus, this really doesn't break any rules at all when you actually analyze it.

Wut? Layers?!

He means that you should think of the Alberti pattern as if the pitches were played simultaneously.

Heckel -

Well not really unless you want to be EXTREMELY strict. First off Alberti basses could be orchestrated in many ways - in this case we can hear the top repeating B as a pedal point held by woodwinds while the E-G third could be orchestrated as tremelo in the string say. In any case, the B would act as a pedal while the E-G would be the more fluid voice. And to simplify it to a vocal texture , it would be simply a E minor chord sung every quarter or half note. So looking at the top note of the chord the B, we have the following intervallic relationships with the figure in the bass - maj 10th- P8-P5.

It is always important to consider the tempo - at the speed this piece goes you would not notice it. Plus if Mozart tried to avoid it with same pitch material, the only option would be to have the B transposed DOWN an octave - which would actually create GREAT discontinuity in the music. As it stands I'd say the parallelism you spot contributes to make the figures sound more galloping than before and in keeping with the feel of this piece.

Who cares if composers break rules of harmony? I've seen Bach do it heaps if times!

Really? I was just stating something. I know it's alberti blah blah blah. I know that it's TECHNICALLY allowed unless in uber-strict rules. But, it's still. parallel octaves not using it as doubling.

Nothing wrong with breaking rules. I haven't written a piece that follows the rules unless it's an arrangment in years.

No need to get fussy over this. It's just a little detail that I find interesting. But he did break other rules too, which is okay. I was only pointing out a non-doubling use of parallel octaves.