harmonic major - are you aware of any scales that can be harmonized into interesting modes of unique flavor? I imagine I can come up with a few with two half steps in a row, but that seems like the middle note would just act as a passing tone, right? Or could complex harmony exist with a scale with three notes in a row?
A: If you mean harmonizing to chords, The half/whole diminished scale does some interesting things. It has a bunch of major triads in it so there are various slash chord things you can do. It is symmetrical so it doesn't turn into modes though.
If you want to talk about harmonizing to chords, let's talk first about the half/whole diminished scale. It is a symmetrical scale which makes it unlike all other scales (the other symmetrical scale is the whole tone scale, all whole steps).
Here is a standard pattern for the scale:
We can have a bunch of fun here. The scale is spelled 1-b2-#2-3-#4-5-6-b7 (all half and whole steps). We generally use this scale over a dominant 13 chord with a b9 or #9 as in 13b9 or 13#9.
But there is other fun things you can do. Let's use C as our example: C-Db-Eb-E-F#-G-A-Bb. So lets make chords (triads): C-Dbdim-Eb-Edim-F#-Gdim-A-Bbdim. You can have fun by using the four triads as slash chords. What I mean by this is, let's say for example, you have C13b9 written on your chart (or any dominant chord which you want to treat like a half/whole diminished scale chord). You can play: C - Eb/C - F#/C - A/C and all these slash chords will function as some sort of half/whole diminished dominant chord. Let's examine why exactly:
C = C
Eb/C = C7#9 (intervals: 1-#9-5-b7)
F#/C = C7(#11,b9) (intervals: 1-#11-b7-b9)
A/C = C13b9 (intervals: 1-6-b9-3)
How cool is that? Especially as if you start with the C chord, it goes from inside to outside. You can use this as an improv idea as well playing arpeggios.
More fun with chords from this scale here>>>
On to the second part of my answer to your question.
There is so much to work through with the modes of melodic minor alone, that I've never really considered other scales, much less modes of any exotic scales very much.There is one scale that is interesting to me though, it is a melodic minor scale with a flat 2. There is an other post on my blog about it here >>>
The scale, as the name implies, is a melodic minor scale with a lowered 2nd: 1-b2-b3-4-5-6-7. As any scale, it can be broken down to seven modes but the one that interests me the most is the fourth mode which looks like this: 1-2-3-#4-5-b6-b7. I don't know what the name technically is, but by the way it looks, I call it a lydian dominant b6 scale. Before getting into this particular scale in more detail, let's take a look at what all the modes would be (I don't know of any standardized names for these modes so I'll just be making some up as I go based on the intervals):
1-b2-b3-4-5-6-7 = melodic minor b2
1-2-3-#4-#5-b7-7 = whole tone major (it is basically a whole tone scale with a major 7 stuck in it.
1-2-3-#4-#5-6-b7 = lydian dominant #5 (I haven't actually tried it but it looks workable to me simple because of the possible chord: 7#11 or 7#5).
1-2-3-#4-5-b6-b7 = lydian dominant b6 (I like this one. I sounds spice over a static major triad, 7, 9 or 7#11 chord).
1-2-3-4-b5-b6-b7 = locrian major (freak out! Don't know what to say about this. Just have to try it out over a 7#5 chord).
1-2-#2-3-b5-#5-b7 altered natural 2 (plain old altered seems like a much better choice. But I guess there are such things a 9(b5) or 9(#5) chord. But then again, we have the whole tone for things like that. Don't know really, give it a shot.
1-b2-2-3-#4-#5-b7 = lydian dominant #5, b2 (sort of freaky but probably workable over some kind of 7#5 chord.
So there you have the modes. With the exception of the lydian dominant b6 scale, I haven't tried all of them really so proceed at your own peril.
As I said, I like #4 a lot. Give it a try over a static E chord: