Theory question...

[perfect_pitch]

Greetings... I'll make it quick. Which one of the following harmonies are technically right according to the basic rules of 4-part harmony???



Image 1 (above) technically has Parallel 5ths on the 3rd and 4th quaver beats in the Alto and Tenor voices (although the 3rd beat is technically a diminished 5th), however....



Image 2 (above) omits the 5th note of the chord on beat 4, although it helps avoid the parallel 5ths.

I ask because it's been a LONG while since I did Grade 4 AMEB theory.

[rachmaninoff_forever]

Parallel tritones are fine.  Sorry, I mean diminished 5ths.

And the second one is fine as well.

[Bob]

Just looking... I'm thinking both are correct.  I haven't messed with part writing for a long time either.

Hm...  d5 to P5.  It's parallel perfect fifths that is the problem to avoid.  I thought.  

... Unless someone's taking the most important chords... Starts on I with P5 in LH.  Ends on Eb with a P5 in the LH.  I don't think that's technically parallel fifths anymore though.

That might be... Discovered fifths?  There's another one like that.  You have P5 to d5 to P5.  That's probably the problem.  I'd go with the second one being more correct.  

[mikeowski]

There's a parallel octave in image 2 on the last beat.

[quantum]

A slight bending of the rules is fine if it results in a more elegant musical solution. 

Of course this is only a very short excerpt.  If we were given greater context, one could provide more possible solutions.  Things to consider: Where is the key center?  Does the music that follows move to a different key through tonicization or modulation? The given time is 6/8, presuming the music is compound duple the last chord - Eb - falls on a weak subdivision.  What is the chord that follows on a strong beat?  These questions have bearing on the possible solutions to the harmony. 

[perfect_pitch]

There's a parallel octave in image 2 on the last beat.

How the BLOODY hell did I not see that??? I've been doing Cadences, 4-part writing all week, and I didn't even spot that. Thanks.

You have P5 to d5 to P5.  That's probably the problem.  

But the first P5 is in the Tenor & Bass... the other 2 intervals are in the Alto & Tenor. What's wrong with that?

[rachmaninoff_forever]

There's a parallel octave in image 2 on the last beat.

Dang I didn't even see that!!!

[Bob]

How the BLOODY hell did I not see that??? I've been doing Cadences, 4-part writing all week, and I didn't even spot that. Thanks.

But the first P5 is in the Tenor & Bass... the other 2 intervals are in the Alto & Tenor. What's wrong with that?

Oi... Nothing.  Haha.  Just ignore me.