im not asking "what i can or cannot play" as all music is subjective, but im asking for "theory" or "technical" reasonings.
people often say that they replace the 4/11 over a Major chord, primarily with the tonic Major chord, with the #4/#11, so to avoid the tension between the M3 guide tone. so what they are really saying, in technical terms, is that they prefer a Lydian sound over an Ionian sound?
My confusion comes from the fact that if we build a tertian harmony sequence of diatonic notes, over a CMaj scale chord, in the key of C, you will have the "avoid note" of [F] as the diatonic 11th (ie; C-E-G-B-D-F). Its as if the chord is its own worst enemy, if that makes any sense lol The tonic chord is meant to be "at home", yet if built up until the 11th is reached naturally, it creates this conflicting sound.
This is mostly regarding the tonic Major, as the other true Major chord of the scale is the subdominant (IV), which is naturally the Lydian chord of the scale. So technically, the (IV) cannot be voiced in such a way to naturally create this "avoid" note scenario, if one were to use just the notes of the corresponding parent scale. (ie; using the notes of C Ionian or F Lydian, etc.)
However, if in the key of CMaj, you decided to play [F Ionian] over the [IV] chord, you would then be intentionally creating the "avoid" note 4/11 scenario?
So, if you have a typical [1-5-6-4] pop or rock progression in CMaj & you voice the 1 chord as having the , that means you are strictly implying an "Ionian" sound? However, if you voiced it to have a [#11], you would imply a Lydian sound, just over that 1 tonic chord, although the entire progression or piece would still be considered a CMaj key?
If a progression was "modal" on the other hand, such as a [C Ionian] progression, then that means you would SPECIFICALLY use notes like the [4/11] & the ... not only over the [I] chord, but as often as needed over/under other chords in the progression as well? For example, a pure Ionian progression could be [CMaj(add11)-> FMaj-> CMaj-> bdim]?
So when other sites & sources describe the [4/11] as an avoid note, they are perhaps speaking from a primarily "tonal" chord voicing or progression standpoint & are simply saying, in reality, they prefer a Lydian sound, rather than an Ionian voicing?
I know nothing is stopping us from using a CMaj(add11) chord, in a "tonal" progression, as mentioned above, though... if it sounds good to you, that's all that matters, but Im simply trying to understand things from a theory, technical or "historical" point.