Re: question about transposing an interval of a 4th - Looks like I found the answer

[Francisco Vila]

2009/1/17 Chip <address@hidden>:
> I'll take you word for it because I don't know the difference between all
> the transposition types you mention above, haven't even heard of some of
> 'em.

Actually I've only mentioned two types. Suppose you want to transpose
{ c d e f g a b c } a fourth lower. You could think of { g a b c d e f
g } but this result has the following properties:
Firstly it does not sound as a c \major scale as if it had fis instead
of f. I call this a 'mode' (namely mixolidian) that is not a \major or
\minor scale.

Secondly, of course it is not a _constant_ fourth below the c \major
scale, because { b f } is an augmented fourth, not a just fourth as
all others are in this example and always are inside a \major scale,
except { b f }.

So this type of transposition is called diatonic, it has not constant
fourths apart from your initial scale and it looks as a g \major scale
adapted to the c \major note set.

\transpose would have produced { g a b c d e fis g }, this is a 'real'
transposition, it is always a just fourth interval from { c d e, etc.
} and it sounds just like a g \major scale, of course. Your 'manual'
adjustment has to bring the 'fis' back to 'f' so you do not go out of
the c \major note set, this modifies the type of fourth interval from
just to augmented.

Keep interval, let scale to be modified --> real transposition.

Let interval to result modified, keep scale --> diatonic transposition

-- 
Francisco Vila. Badajoz (Spain)
http://www.paconet.org