Modes are trippy things… They are way more related to each other than they might seem, in fact they are all using the same relationship of spacing between notes just starting from different points. I’ll try to explain.
Western music is comprised of 12 notes. The modes use a group of seven out of the twelve notes. Take the basic major scale. Let’s use the sound of music…
do re mi fa so la ti do
That’s 8 notes but as you see there are two "do"s, the last one is an octave up from the first one, so really there’s seven notes…
Do is the root note of the major scale which is actually the Ionian mode.
What it is is a pattern or spacing between notes you play. Each note in the scale is either a 1/2 step(the very next note) or a whole step(skip one note) from each other. With C as the root it goes like this:
C major(Ionian)
(Root)-whole step-whole step-half step-whole step-whole step-whole step-half step
—C------------D-------------E-----------F-------------G-------------A----------B--------------C—
—do-----------re------------mi----------fa------------so-------------la---------ti---------------do
What the modes are is instead of starting on do and ending on do, you start with re and end with re, start with mi and end with mi, etc… But using the same spacing of whole steps or half steps for all.
If I were to start with re and end with re, that is the Dorian mode… Re would be the root, and it would go like this:
D Dorian
(Root)-whole step-half step-whole step-whole step-whole step-half step-whole step
—D------------E----------F--------------G-------------A-------------B-----------C------------D----
—re-----------mi---------fa--------------so------------la-------------ti-----------do-----------re—
Starting with mi and ending with mi would be the Phrygian mode, and go like this:
E Phrygian
(Root)-half step-whole step-whole step-whole step-half step-whole step-whole step
–E----------F-------------G-------------A--------------B----------C--------------D------------E----
–mi---------fa------------so------------la--------------ti-----------do-------------re-----------mi—
So there you have the first three modes based off of a root of C…
The rest are fa to fa, so to so, la to la, and ti to ti…
As you can see they are all the exact same notes. C major(Ionian), D Dorian, and E Phrygian are all the exact same notes and relationships between them, just starting and using a different root for each one. Same for the other 4 modes that I didn’t write out…
It helps a lot to understand this, and it gets more complicated, but I won’t go there right now. You can learn them as patterns on instruments and with enough practice they sink into your brain until your fingers just play them.
Personally, again personally, I like to know a bit of theory because it really helps a lot, but I don’t like to know too much as I play by ear too and am always ready to break any rules, it can be easy for trained musicians to get sort of “locked in” to rules, although this is certainly a generalization, but in my experience I’ve seen that a lot with trained musicians I’ve played with.
Hope this helps, it’s a bit mind boggling at first but once you get the relationship of the spacing and how each of the seven modes are all the same notes, there’s a lot you can extrapolate from it, meaning you can figure out more about it just by understanding the primary stuff…
As a side note this is why the A4 and OT arps can play the same scales as the Digitone which I’ve posted charts about how to relate them. They are all the same really, just starting and using a different root for the scale…