movement in parallel 4ths

[tbassist4]

Hello, I have a question that's been bothering me for a little bit. I know it's against the common practice rules of voice leading to move in parallel 5ths, and so I assumed that its inversion, moving in parallel 4ths, was also not allowed. I heard recently however that there's no rule against moving in parallel 4ths, and from my experience, it seems that there is an unwritten rule that it is allowed but discouraged. Am I right in this?

[bopeuph]

Parallel fourths are included in the rule. Parallel fourths, fifths, and octaves are frowned upon. Fourth and fifth intervals are technically different, but in a sense are still the same, just a note is in in another octave.

Nick

[John Wentzien]

That's a throw-back from the "Bach is God" school of music. If it sounds good, do it!

[bopeuph]

This is based on rules after thorough study of Bach chorales. However, it's a great place for someone who is starting classical music composition or theory. Bach did write in this way, and he did break this rule, too, because sometimes, it sounded good. But there is a sound that was very unfavorable from parallel movement, which is why this rule has been made. One has to be careful when breaking rules. There are great examples of rules being broken, and they were tastefully done. You just have to know how to break them.

Nick

[shostkontrabass]

I think it's important to learn the rules before breaking them. That said, parallel movement was frowned upon especially in the past, but it has been used well since then. It's all in how you want the piece to sound, and I think back then people just weren't ready for that sound. Tritones were frowned upon too, but look at how abundant they are now!

[John Wentzien]

I read somewhere that 5ths were deemed "Evil Sounding" by the church, and were forbidden back in Bach days..

[tbassist4]

Originally Posted by John Wentzien

I read somewhere that 5ths were deemed "Evil Sounding" by the church, and were forbidden back in Bach days..

Hahahaha, I'm sorry, you read wrong. Tritones were deemed evil sounding. In Chant, 5ths, 4ths, and octaves were the only harmonies allowed because they are the purest intervals. Thirds were actually considered dissonant at that time.

[bopeuph]

Originally Posted by John Wentzien

I read somewhere that 5ths were deemed "Evil Sounding" by the church, and were forbidden back in Bach days..

It was actually diminished fifths (or augmented fourths or tritones) that was considered evil. It was called "la diablo en musica," which means "the devil in music."

And it was before the days of Bach, more like the medieval and renaissance times. Bach used the tritone quite a bit. This is after the dominant V7 chord had started to be used, which has a tritone in it.

Nick

[tbassist4]

I've been sniffing around a bit, and it seems that parallel 4ths are in a bit of dispute. I've gotten mixed results online and from friends, so I think I'll just ask my theory professor tomorrow in class.

[tbassist4]

I talked to my music theory professor today, and after a few examples, I got the answer. Moving in parallel 4ths is in fact legal. It is an assumption (though a well educated assumption) that inversions are included in the rule set of their root parent. This is not the case.

As I was taught a long time ago by another well distinguished theorist and composer, Bach regarded the (I'll just be using "I" for the example, this can be applied to any chord) I, I6, and I 6/4 as three separate entities, which all had to be used and treated differently. This means that inversions are handled separately from their root counterparts. This includes intervals and movement. Inversions sound similar, but have different characteristics.

In the example I attached, three voices are provided. The first measure includes legal movement of parallel 4ths, and is an example of, as well as is the 6/4 inversion, the most common use of parallel 4ths; a 6 to a 6, or a 6/4 to a 6/4. The second example shows the movement of parallel 5ths; illegal movement. Like I said before, while inversions include the same notes and share characteristics, they are in fact different and therefore have some characteristics that are different from one another.