SloeGin wrote:Hey guys,
Excuse my ignorance, i'm still kinda new to this but i have a theory question.
I'm only really familiar with the minor pentatonic and the aeolion scale.
Let's take the song 'Sloe Gin' for example.
I'm wondering some things:
1).The key of the song is D minor i think since the D minor pentatonic fits perfectly over it. Correct?
I noticed that D Dorian goes too, at least in the first position. Or am i wrong here?
2). What Mixolydian scale can i use here too since the Mixolydian scale is often used in blues?
Hopefully someone here can clear some things up for me 
Thanks in advance!
Natural minor (aeolian), minor pentatonic, dorian, harmonic minor, melodic minor - these are all minor scales that could work in "minor key songs" because they have a flatted 3rd (in the case of D minor, that's an F). That creates the minor sound. Whether the 2nd, 6th or 7th is natural or flat changes the sound of the scale, and will sound "right" depending what chords it's played over, or what chords it's leading to.
You'd use dorian if you want the sound of a minor I chord but major IV chord - think Santana (Evil Ways). D dorian is D, E, F (minor 3rd), G, A, B (natural 6th), C (flat 7). If the song has, say D- as the root, but a G major (or G7) dorian would sound good because you've got the B. That B (natural 6th) in the D dorian scale matching up strongly with the B in the G chord (it's the major 3rd of G). If the song has a D- as the root chord, but a G- as the IV, you probably want to stick with natural minor (D, E, F, G, A, Bb (flat 6th), C. That Bb in D dorian is the flatted 3rd in a G minor.
Since a minor pentatonic scale doesn't have the 6th, it's going to work regardless because it doesn't have that B or Bb.
I haven't played Sloe Gin in a long time, but I remember it being more of a D natural minor type of sound - without hearing it now I'm guessing there's a G- in there somewhere. The theory is nice to help give you a roadmap, and understand and communicate what you're doing, but your ears are the ultimate judge.
C Mixolydian is C, D, E, F, G, A, Bb - (it's a major scale w/ a flatted 7th) which has the same notes as D natural minor, so that would probably work, but it's a really different sound and feel. If there's a strong C7 chord in the progression, you might try playing C mixo over that chord, but honesty, I would tend to think "D minor" for the whole thing because it has that minor type of sound. I'm not sure my brain would be thinking C mixo for a D minor song, because it's such a different sound.
If a progression has chords that don't fully fit in one key (like most jazz standards), then I would tend to think "what fits over what chords" as opposed to "the song is in key X." Not really the most melodic way to play music, but it gets you by... The best thing is to make melodies where the notes happen to fit the underlying chords, whatever they are, but it's tricky for me to do on the fly being a rock/blues guy.
