Is Cmaj7 in the C major scale different than the Cmaj7 in the C Dorian scale?

Question

I was told that the 7 in Cmaj7 indicates the 7th scale degree. But here's what's confusing to me: in the C major scale, the 7th scale degree is B. And the interval from the root note of the Cmaj7 chord to the 7th would be a M7. However, in the C Dorian scale, the 7th scale degree is A#, and the interval from the root note of Cmaj7 to the 7th would be a m7. So if the number 7 in Cmaj7 really indicates the 7th scale degree, then does that mean Cmaj7 in C major scale is different than Cmaj7 in C Dorian scale?

Answer 1

The C Major scale is C D E F G A B and the formula for a major scale is 1 2 3 4 5 6 7. This is also referred to as the Ionian Mode, and it's parent Key is the key of C (no sharps/no flats)

Modes are not Keys. Modes are scales that start from various notes within a Key. The Dorian Mode is a scale that starts on the second degree of a Major Key. The Dorian mode in the key of C, for example, would be D Dorian

When we use numerical analysis of modes, we compare all modes to the major Key that would start on the same scale degree to determine their formula. In order to find the numerical values for C Dorian, we would have to determine its parent key, then compare it to C Ionian

C Major (Ionian) yields a CM7 because the notes in a CM7 are (C) D (E) F (G) A (B) - CDGB

C Dorian would be from the parent key of Bb Major (2 flats, Bb & Eb), as "C" is the second scale degree in the Bb Major (Ionian) scale Bb >(C)< D Eb F G A - 1 >(2)< 3 4 5 6 7

So we would then do a cross-analysis of C Dorian from the parent Key of Bb Major with C Ionian from the parent key of C Major

This means the C Dorian Scale would be (C) D (Eb) F (G) A (Bb) - Cm7 - (1) 2 (b3) 4 (5) 6 (b7)

Compared to the C Major Scale (C) D (E) F (G) A (B) - CM7 - (1) 2 (3) 4 (5) 6 (7)

C Dorian (parent key Bb Major) yields a minor 3rd and minor 7th, also noted as b3 and b7

C Ionian (parent key C Major) yields a major 3rd and major 7th, also noted as simply 3 and 7

Answer 2

No. The C Dorian scale would have two flats whereas a CM7 would not have any flats. Remember that the modes are based on different combinations of half and whole steps. Implement the "formula" using the tonic to begin the formula and to create the desired mode. There is no A# in the C Dorian scale whose pitches are: C D Eb F G A Bb C