Four Part Writing - Root Position Rules

Hi,

I have some quick questions that have been bugging me over the past few weeks.

Direct/Hidden Octaves & Fifths

I have seen that you cant approach a P5 or P8 by contrary motion. I read that online, but it's not in my harmony book. Is it correct? Or just not part of the common practice period? Also, I'm confused about approaching P5 and P8 by similar motion. I've see some conflicting information on this:

1.You can forget this rule altogether in 4 part textures.

2.It is only restricted to the outside voices, Soprano and Bass.

3.You must check for this in all voices, like when you check for parallel P5s/P8s/PUs.

Which one is right? Should I just continue checking for it in all voices?

One last thing? Does every voice have to be followed by the closest note? From V-I the D can ascend a M2 to E or descend a M2 to C. Any particular preference here? Or just go with whichever fits the situation?

With regards to parallel motion, are parallel 2nds OK? They aren't mentioned anywhere I've been. I know that 3rds, 6ths, 4ths and tritone are all OK, but just curious why 2nds/7ths are not mentioned.

Thanks for your time.

regards

TheAristocrat

It really depends on the style and the period in question.

But generally, with regard to common practice period:

Direct/hidden perfect consonances (8ves and 5ths): This can vary from theorist to theorist. Check all your voices to make sure you familiarize yourself with the voice-leading principles and are not missing something. Hidden 8ves and 5ths are most often considered bad if they are between the outer voices (bass and soprano) with soprano moving by skip, which would bring too much attention and put accent on the event.

The general voice-leading principle is to move voices smoothly to the closest possible tones, but this could be violated sometimes when it is justified by another important factor - for example, if you want all the chord tones present at a cadence and it is not possible otherwise. In such cases you can even leap a 7th and/or NOT follow scale tendencies. However, this should occur between inner voices, because it is not so noticeable and disturbing.

2nds/7ths are considered dissonances that should be resolved and they usually dont't occur in succession. But this is true only for the common practice period. 3rds and 6ths can obscure the independency of the lines if there are too many in succession. I wouldn't use more than three, especially between outer voices. You can freely leap when making exchange while staying in the same harmony, which is basically a form of arpeggiation.

As for the V-I, I guess you are in C major... It depends on the context, inversion and doubling, but if you have, for example, G-G-B-D and are resolving to a root position triad, then, if the tenor stays the same, you would most probably want to move D to E thus providing the third of the tonic chord (that's a pretty regular resolution from melodic point of view). Moving D to G would give you antiparallel fifths between the upper voices, which I would avoid. If you are resolving to a 1st inversion triad, it is generally preferred to double the root or the fifth, so in this case D would move to C or G. Depending on the context, it is also possible to double the third, though maybe I would prefer to avoid progression from perfect 5ths to perfect 8ves between the upper voices, but this isn't so crucial.