How can perfect fourths/fifths work?

Galaxo

New member
Hey guys,
I'm from Slovakia and I learn music theory in school, so I don't know all of the english words of it, so sorry about that. Anyway, in many tutorials people tune different oscillators apart, like OSC1 is +0 semitones and OSC2 is +5 semitones. But how can this work? I'll give you an example, let's say we're in C Major and the synth that has the oscillators tuned differently is playing the note C (greyed out notes are not in key/scale) :
B
A#
A
G#
G
F#
F-OSC2 (5 semitones up; perfect fourth, correct?)
E
D#
D
C#
C-OSC1

But what if I want to make a perfect fourth from F?
B
A#-OSC2 (5 semitones up; perfect fourth, correct?)
A
G#
G
F#
F-OSC1
E
D#
D
C#
C
And A# is out of the C Major key/scale.
Even perfect fifths don't alway work, look, we'll be in G Major now (has F#) and the note played is F#:
D
C#-OSC2 (7 semitones up; perfect fifth, correct?)
C2
B
A#
A
G#
G
F#-OSC1
F
E
D#
D
C#
C1

I'm not even too good at music theory, but I just can't understand this. Help?
And BTW: what's the difference between Key and Scale?
 
Hey guys,
I'm from Slovakia and I learn music theory in school, so I don't know all of the english words of it, so sorry about that. Anyway, in many tutorials people tune different oscillators apart, like OSC1 is +0 semitones and OSC2 is +5 semitones. But how can this work? I'll give you an example, let's say we're in C Major and the synth that has the oscillators tuned differently is playing the note C:

I'm going to recast your questions and examples into a single table so that we can see what is really going one

NoteExample 1 (4th)Example 2 (4th)Example 3(5th)
D
C[sup]#[/sup]/D[sup]b[/sup]OSC2
C2
B
A[sup]#[/sup]/B[sup]b[/sup]OSC2
A
G[sup]#[/sup]/A[sup]b[/sup]
G
F[sup]#[/sup]/G[sup]b[/sup]OSC1
FOSC2OSC1
E
D[sup]#[/sup]/E[sup]b[/sup]
D
C[sup]#[/sup]/D[sup]b[/sup]
COSC1

Example is a perfect 4th from C-F
Example 2 is a perfect 4th from F-B[sup]b[/sup]: B[sup]b[/sup] is out of the C Major key/scale, but is not necessarily invalid for the context you have create by using a patch tuned in 4ths.
Example 3 is a perfect from F[sup]#[/sup]-C[sup]#[/sup]: C[sup]#[/sup] is not the scale of G major but it may be just as valid as your other patch.

This sort of thing will happen whenever you choose to use a fixed interval approach to creating patches or harmony.

And BTW: what's the difference between Key and Scale?

A key is the selection of notes that are fixed in position for a specific starting note. The scale is all notes including those fixed notes in sequence. E.G. The key a F major has a B[sup]b[/sup] in it. the scale is F-G-A-B[sup]b[/sup]-C-D-E-F
 
Last edited:
I'm going to recast your questions and examples into a single table so that we can see what is really going one

NoteExample 1 (4th)Example 2 (4th)Example 3(5th)
D
C[SUP]#[/SUP]/D[SUP]b[/SUP]OSC2
C2
B
A[SUP]#[/SUP]/B[SUP]b[/SUP]OSC2
A
G[SUP]#[/SUP]/A[SUP]b[/SUP]
G
F[SUP]#[/SUP]/G[SUP]b[/SUP]OSC1
FOSC2OSC1
E
D[SUP]#[/SUP]/E[SUP]b[/SUP]
D
C[SUP]#[/SUP]/D[SUP]b[/SUP]
COSC1

Example is a perfect 4th from C-F
Example 2 is a perfect 4th from F-B[SUP]b[/SUP]: B[SUP]b[/SUP] is out of the C Major key/scale, but is not necessarily invalid for the context you have create by using a patch tuned in 4ths.
Example 3 is a perfect from F[SUP]#[/SUP]-C[SUP]#[/SUP]: C[SUP]#[/SUP] is not the scale of G major but it may be just as valid as your other patch.

This sort of thing will happen whenever you choose to use a fixed interval approach to creating patches or harmony.



A key is the selection of notes that are fixed in position for a specific starting note. The scale is all notes including those fixed notes in sequence. E.G. The key a F major has a B[SUP]b[/SUP] in it. the scale is F-G-A-B[SUP]b[/SUP]-C-D-E-F

Does that mean that's its okay to use a fixed interval in a synth even if some notes will be off key? If yes, then what are even keys for?
 
Your question is too broad to answer as a yes/no.

As I said above , if the context you have created by using that patch allows for the out-of-key notes to appear, then there is no-harm-no-foul.

You are also trying to apply an 18th and 19th century harmonic rigour on something that is a late 20th century invention (at least in terms of mass-ownership).

the long and the short of it is if it works use it, if it doesn't don't.

Keys exist as scaffolding - we deviate from them all the time when creating music, but they are the guidelines within which some feel compelled to stay whereas others feel compelled to break loose and explore.....
 
Your question is too broad to answer as a yes/no.

As I said above , if the context you have created by using that patch allows for the out-of-key notes to appear, then there is no-harm-no-foul.

You are also trying to apply an 18th and 19th century harmonic rigour on something that is a late 20th century invention (at least in terms of mass-ownership).

the long and the short of it is if it works use it, if it doesn't don't.

Keys exist as scaffolding - we deviate from them all the time when creating music, but they are the guidelines within which some feel compelled to stay whereas others feel compelled to break loose and explore.....

Thanks, as I said before I don't know THAT much about music thoery, I just saw many tutorials using the fixed intervals in the synth's oscillators, and I read an article that said that perfect fifths and fourths are commonly used in progressive house. I guess I'll just use my ears to find out if it works.
 
Back
Top