Good afternoon everyone!
Sometime 2 years ago I started practicing voice leading for 4 voices, but since I had to spend all my time on school I kind of stopped halfway. Since I graduated I've picked up practicing it again from the beginning (using a book) and I'm somewhat confused about the rule regarding hidden fifths/octaves.
I have to harmonize connections on I - IV - V in root position, but I feel like it's nearly impossible to avoid hidden fifths/octaves at all. The book stated that they are OK in the outside voices if the interval in the bass is bigger than the interval in the soprano, but if they appear between the other voices, "the ear has to decide" if it's acceptable or not. Now my musical ear is developed pretty well but I think this rule is a bit too vague since what one thinks is OK, the other may disagree.
So my question: What exactly are the rules stating whether hidden fifths/octaves are acceptable or not?
This is a little exercise I did yesterday. You get a given bass in root position and you have to harmonize the chords. I haven't checked the exercise entirely yet, but as you can see, there's a hidden octave between bar 2 and 3 between the bass and alto going from A - C to D - D. I could make the alto go from C to A below instead to avoid that, but then there would appear a hidden fifth between the tenor and alto and I believe that's worse than the current situation I'm having now. As far as I can remember my music teacher once said that they are allowed, AS LONG as the lower voice has a bigger interval than the upper voice. Can somebody confirm this?
(PS. Don't mind the erase marks etc... It's difficult focussing at 1 AM... ^^)