Often, in improvisation, you think of the notes of the scale not as the actual notes you are playing but as the notes of the C scale. The concept I'm talking about is that of the movable C, or something like that. To give you an example, if I'm playing the E minor scale, I'll place myself on E as the reference note but then start the different sounds of the scale as if that central note was an A and the scale was A minor. Is it really important to set your mind and practice to come up with those notes in an absolute sense? I know no musician would ever answer that this kind of work is pointless, but does it really make a difference to making the leap? How does the professional's mind work?
Well, what you describe is sort of like transposing of scales. Play
E minor, but mentally transpose to
I wouldn't call that absolute to relative. I would call that absolute to... another absolute scale.
What I suspect you mean, or may have heard but misunderstood, it thinking of scales and tones in relative terms, relative to a tonic or relative in terms of intervals. For example instead of thinking
G, think in
E minor "tonic" to scale's "third", or in simple interval terms "up a minor third." You could also think in intervals relative to chord tones or the chord root. For example, you're playing an
A major chord and you drop the
A down (by interval) a whole step to
G to make
Solfege is another relative way of thinking about harmony and melody, but it seems to be popular only in classical style. That isn't a problem, it just means it unfamiliar to a lot of people. Similarly, terms like tonic, mediant, leading tone, etc. are all relative terms, labels to scale degrees relative to a tonic tone.
That is the relative way of thinking about harmony and melody and it's very much normal. IMO to not think in this relative way often betrays a basic understanding of how harmony works, or how melody works linearly in the harmonic context.
Sometimes a music lesson may put things into
C major because it's considered an "easy" key. Easy to read in notation, easy on piano, because it's all the white keys, no black keys. Or, you might hear something like "the mixolydian scale is like a major scale with a lowered seventh degree, or
C major with a
B flat..." Something like that. The point is not to literally transpose to, and think of everything in terms of
C major, but to provide an easy point of reference. Imagine if all your musical examples were given in
G flat major or
E flat minor? Chromatic spellings and relative relationships would be hard to follow.
C major, all naturals, is sort of neutral. But, mentally transposing to absolute pitches of
C major isn't necessarily the thing to do all the time. Most likely not what you want to do while improvising.
Edit after more comments on OP. Here's an example "finding" dorian mode:
- Find the tonic on your instrument
- Dorian is in the family of three minor diatonic modes which share this template of common tones:
T _ ♭3 4 5 _ ♭7 T
- Dorian fills in the missing notes with natural
- Relative to the tonic those are a major second and major third respectively
Instead of thinking of dorian as the second rotation of a
C major scale we think in terms relative to the tonic and relative to a family of minor modes. And the added benefit of thinking this way is the other two minor modes - aeolian and phrygian - are just a matter of tweaking those second and sixth degrees.
Your first sentence. No, I don't. I think in the key I'm playing in. If I started doing what you say we do, it'd be all over the place.
It may be that you are well versed in movable do, and thus use key C as the reference point, but that then adds an extra layer to what you're doing, for no good purpose.
And the minor reference just doesn;t make sense, even using Am as the relative to C major.Reverting to key C each time for me at least has no productive purpose. Say you had a really complicated piece, with many chord changes, and lots of chords, with extensions, please explain how (and why) referencing that back to key C has any advantages. Let alone what happens when modulations or key changes occur.
I'm guessing that you were brought up with movable do solfege, in which case what you do might make more sense. But then you refer back to do in the 'white keys' key, of C?