Correct, Alt moves diatonically. Shift-Alt move chromatically, Ctrl-Alt shifts by octave.
The chord thing is a brilliant idea. Perhaps Ctrl-Alt-Shift-up/down…
It could be mapped to different keys, but I really don’t think that would be necessary. If a chord is present, use it, otherwise use the key signature as usual. And there could certainly be a user preference setting to never use the chords – for those who would find this behavior confusing. But if it is a different key sequence, that would be OK.
For me, this would help me get good voicings when we have more dense chords like C7#11 (lydian scale), C7b9 (a mixolydian scale, but with a flatted 2nd) and so on. This would not be perfect in every case, but on balance I think it would do more good than harm, and I can also use Shft-Alt-Up/Down to adjust semitones in those imperfect cases.
Yes, without a doubt the quickest method at the moment! Thank you for explaining it so well, graphic and everything! Hopefully the developers are watching this thread and they’ll come up with a more efficient (i.e. quicker) method in the future.
I am in no way objecting to this being added, but I do wonder how useful it really is considering you wouldn’t want to harmonise every note using chord tones. It would create a rather dull harmonisation… As Sammy Nestico used to say, “you should never use the same harmonisation technique for more than a bar”. Perhaps in Pop music it has more uses…
Ideally I agree, but the reality is that lots of these sorts of things have to be “quick and dirty.” There are plenty of times I just have to crank it out. And part of my growth as an arranger (I hope) has been knowing when laborious details on a particular section are really helpful and perceptible, and when a simple “explode” (or “harmonize this chord”) will do the job well enough.
Just to be clear, what I am talking about is the chords (if present) defining an alternate SCALE, upon which the diatonic move (Alt-Up/Down) would operate. Therein lies some of the ambiguity and artistry. There would have to be decisions about which notes make most sense for each chord. I would always favor color tones and guide tones over the basic tones.
I think what Nestico was talking about was more about the method (tight voicing, drop-2 or whatever) rather than the actual harmonies. What I am talking about is getting help from Dorico to take me to notes that are “best” for the current chord. This in no way would impose the voicing method. If I wanted the part to be a third below, I’d hit alt-Down twice. It I wanted a 6th below, I’d hit alt-Down 5 times, and the resulting 6th might be perfect, diminished or augmented, depending on the relationship with that chord. And I I didn’t like that, then I’d use Shift-Alt-Up/Down to put it exactly where I wanted it.
The key point is that my workflow would typically be to select an entire phrase of notes and apply this “smart diatonic” change to the entire phrase, and then adjust individual notes per the Nestico advice.
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And looking longer term, If Dorico could become “harmonically aware” (either through the explicitly entered chord names or by algorithms that can infer the chords), it is a relatively small step to offer a “Chord explode” according to whatever harmonization method the user wanted to try. Finale had a Band-in-a-Box harmonization module that did exactly this, offering many different harmonization methods. It had some issues, but fundamentally I think the concept is viable. It just needs a better implementation. I would never expect such an algorithm to produce the final product 100% of the time. But it could save hours of time (and errors) in any arranging project.
So, so true… Not too mention most “commissioners” won’t even notice if you do ‘fancy’ harmonising… 
I’m not disagreeing with you at all, but out of sheer speculation I would think he meant more in the sense of the type of technique used, not necessarily the voicing. For example: variable voicing technique, where the harmony is dictated by the intervals of the melody, or chromatic voice-lead, where harmonies move chromatically instead of diatonic, normally in opposite direction of the melody. And of course there’s also open voicing, rootless harmonies, Hi-Lo voice tension movements, dominant and diminished approaches to down beats, etc.
In other words, there are so many different harmonising techniques that use non-diatonic harmony notes, whereas there’s only about three that do use them and mostly on downbeats… Just a thought.
Those are interesting thoughts that I appreciate. I think they are a little more applicable to a large ensemble (e.g. big band). There are all sorts of times that 2- and 3-voice ensembles use what I would think of as diatonic voicing (but within the chord scale, not the key signature scale). By this, I mean the harmonies move in parallel, based on some interval, 3rd, 6th, 7th, whatever. Of course this might alternate between unison and harmony, or change methods after a few bars. I am just looking for some help from the notation program to let me work faster with fewer blatant errors. And yes, this particular idea would really fit for parallel movement Anything using counterpoint or other intricacies might require doing it the hard way. But even in counterpoint, sometimes it works for the second statement to echo the first statement more or less. In that case, a cut and paste together with this diatonic movement might be helpful.
I would encourage you to look into Cubase (and other DAWs that are supporting chord tracks.) When you cut and paste with chord tracks active, the notes can automatically change to conform to whatever chords are defined for the target measures. This is very powerful and this REALLY, REALLY ought to work in Dorico as well as it works in DAWs. Admittedly, “chord tracks” is more oriented to the rock or pop singer/songwriter, who doesn’t deal so much in dense chords. But it is something, and powerful even in today’s incarnation. After all, even the most avant garde jazz still uses simple harmonies part of the time.
I realize this may seem like a meandering stream of consciousness. My main point is there is a rich opportunity out there and we need to find out how to unleash that.
Hmm, yes I see… I suppose I never harmonise like that i.e. in parallel, not even in the rare pop projects I’ve done. I have known the chord track system in Cubase but I didn’t understand what it was for for years! And then a colleague explained it to me and realise it is for people that write different from me. I’ve always been a paper-pen guy and never been able to write music in a DAW… None, zero… Ha! I just can’t hear or think that way… 
Same with ‘grooves’, I always just write my own.
We all have to find technology work-flows that match our “brain work-flows”. Nobody says we all have to work the same way. It is the variety that makes it art.
But let me offer a tiny example. Let’s say you are 95% done with a composition or arrangement. It is sounding good, but in bar 26, beats 3 and 4, maybe it would be better to change that Dmi7 to a Dmi7(b5). No problem. Simply change the chord symbol and all the A-naturals in any of the parts automatically change to A-flats. You don’t have to hunt them down individually and possibly miss one.
Beautifully put!
Yes, I can certainly see why that would be useful or at least a colour highlight indicating notes that might clash… Like a proof-reading tool. The difficulty would of course be how to implement such a thing and are the numbers of people needing this thing a big percentage? Because for example, I would most definitely not appreciate the software changing my harmonisations when I change the chord symbol, since an Ab over a Dmin is what I call a Q note and I most certainly use that sound a lot (not to mention the chromatic approaches referred to earlier). And then of course you the have the issue of what has priority over what? Your example is good, because you’re unlikely perhaps to have an A against a Dmin7b5, but what about a b9 or #9 over a dominant, an F#’ against a Cmaj, both 7ths on a minor, etc. Furthermore, what about the scale??? I don’t expect computers to be able to do harmonic analysis this century and this comes from someone that reads about the latest in AI on a weekly basis. In a Cmaj7-Dmin7-Emin7 progression, should the programme highlight an F# over the Emin? Should it know that it’s a modal interchange or should it assume it’s diatonic…? Considering that Ai still doesn’t understand that people carrying an umbrella means it might be raining outside, I can’t imagine them being able to figure out the intricacies of tonal music… After all, most Pros don’t… 
Certainly food for thought!
Theory is fine, so long as you realise that almost all of it is 100% retrospective. You look at what people have already written, and try to find patterns in it. I suspect you would be hard pressed to find more than 5 or 10 examples of theorists who came up with some previously unknown piece of music theory, and then wrote music based on their new idea that has become “mainstream”. (The first two that come to my mind are Rameau and Schoenberg).
FWIW I never think along the lines of “what it I tried a Dmi7(b5) chord here” when writing something. I just think about what I want it to sound like!
Yes, I absolutely agree. J.S. Bach didn’t have “theory”. He knew what he wanted his music to sound like and just did it. It was up to academics (who needed a pedagogy to support their enterprise) to study the work and divine the “methods to his madness” so to speak. The last decade of Bach’s life, he did offer “The Art of the Fugue”, but even that was mostly by example rather than theory per se.
As Ellington said, if it sounds good, it is good.
Remember that there was no “jazz theory”, per se, for the first 100 years of American Jazz – if you trace the roots back to the spiritual music on the slave plantations. It wasn’t until the 1960s or so that David Baker and his contemporaries started to develop what we would call theory. And today, a player wanting to make a career of jazz doesn’t have a prayer unless they go through Berklee, Indiana University, North Texas or one of the other great jazz conservatories. Seems a bit ironic that an art form that was built on spontaneity would have ended up here.
Anyway, regardless of where a person comes from and how they get there, I want all the useful tools I can get my hands and ears on.