Hi! Is there a way to get chords built on a particular scale by specifying the degree? I'm thinking something like the chord_degree function in Sonic Pi that takes degree, root note, scale and number of notes and returns a list of midi notes:
(chord_degree :i, :c4, :major, 3)
> 60, 64, 67
(chord_degree :ii, :c4, :major, 3)
> 62, 65, 69
(chord_degree :vii, :c4, :major, 3)
> 71, 74, 77
Can I achieve something similar in Tidal? Maybe composing "scale" with some other function?
Hi, yes you can do it in the mini-notation, e.g.
n "c4'maj'3i"
the first bit is the note and octave, then chord, then number of notes and the degree. I just noticed that degree only accepts a succession of is, I'll make a note to fix that..
Thank you, that's exactly what I was looking for.
After further inspection I realized that adding degrees in the mini-notation does something different from what I expected. The Sonic Pi chord_degree I was referring to actually returns the chord built on the specific scale degree, picking notes from the original scale but respecting the intervals, thus giving you the classic chord progressions. For the C major scale that would be:
I ii iii IV V vi vii(diminished)
Cmaj Dmin Emin Fmaj Gmaj Amin Bdim
For example:
(chord_degree :ii, :c4, :major, 3)
# 62, 65, 69 -> D minor (degree ii of the C major scale)
(chord_degree :vii, :c4, :major, 3)
# 71, 74, 77 -> B diminished (degree vii(dim) of the C major scale)
Both these chords (Dmin and Bdim) fit in the C tonality and are built on the C scale.
What Tidal does instead I think is looking at the degree specified, picking the notes that compose the original chord, applying an offset and adding the same notes on top from an octave above. For example:
d1 $ arpg $ n "c'maj'4ii" # sound "superpiano"
-- same as:
d1 $ arpg $ n "[g5,c6,e6,g6]" # sound "superpiano"
d1 $ arpg $ n "c'maj'4iiiiiii" # sound "superpiano"
-- same as:
d1 $ arpg $ n "[e7,g7,c8,e8]" # sound "superpiano"
If I'm not mistaken these are all C chord inversions, but my knowledge of musical theory is not so good, I might be wrong 
You're correct, that notation is for inversions, not referencing scale degrees
This is an interesting problem, you could build triads using mini notation, then describe the interval change:
d1 $ n (scale "ionian" "[0,2,4]") |+ n "<0 1 2 3 4 5 6>" # s "superpiano"
That should play the triads (built in the scale section), with the degree of the scale described as n - 1 after the |+
Not intuitive relative to normal music notation, but at the very least trying to describe the intended outcome to @yaxu
@cleary I came to a similar solution, maybe a bit more "intuitive":
-- degree IV of the D major scale:
d1 $ n (scale "major" ("[-1,1,3]" + "4") + "d5") # s "superpiano"
-- simple progression (I IV V ii) in D major:
d1 $ slow 2 $ n (scale "major" ("[-1,1,3]" + "1 4 5 2") + "d5") # s "superpiano"
-- same as:
d1 $ slow 2 $ n "d5'maj'3 g5'maj'3 a5'maj'3 e5'min'3" # s "superpiano"
-- simple progression (I III v VII) in E minor:
d1 $ slow 2 $ n (scale "minor" ("[-1,1,3]" + "1 3 5 7") + "e5") # s "superpiano"
-- same as:
d1 $ slow 2 $ n "e5'min'3 g5'maj'3 b5'min'3 d6'maj'3" # s "superpiano"
It would be nice to have a dedicated function that could take also roman numbers for the degrees and a chord type (e.g. "maj" instead of "[-1,1,3]") but I'm really a beginner at Haskell 
Cross linking:
Cross linking
This is one of the topics I've been working on a lot lately.
My motivation was to make some rules accessible via TidalCycles using the system of western music theory that I am familiar with. However, I attach great importance to defining and transforming chord progressions and notes with patterns, in order to be able to use the strengths of TidalCycles flexibly here.
There are now a lot of ideas flowed in here and I have collected everything here once. To give you an idea, the usage in TidalCycles looks like this:
do
-- Define chord progressions with roman numerals
s1 = sheet {key = "c", mode "major", numerals = "<1 1 4 5>"}
-- The chord will be created on their elements like
-- root (1), major/minor third (3) and perfect fifth (5).
-- And the chord progressions is based on the sheet.
-- This will play <Cmaj Cmaj Fmaj Gmaj>
d1 $ s "superpiano" <| prog s1 "[1,3,5]" |- note 12
-- Create a melody with the chord changes but use
-- diatonic notes outside of the chord
d2 $ s "superpiano" <| prog s1 "1 5 7@2 3 6 8@2"
I addressed a lot of western harmony concepts like secondary dominants, tritone substitution, borrowed chords and inversions. And you can play a harmony in one scale (like major) and the melody in another scale (like minPent).
Personally, I'm able to code melodic sets much more specifically live with it. I also use it to write flexible backing tracks/loops for the guitar.
If you are interested in such stuff, here is the complete post:
hey @mrreason i am getting hung up on this portion of your code.tidal...it won't evaluate for me. do i not have a certain extension/package installed? any other ideas?
-- Used for using parts and segments
stacker = Map.fromList
(!) = (Map.!)
transformStacker parts = stacker $ map (\x -> (fst $ head x, transform x)) (transpose $ filledWithSilence parts)
where allowedAndNeededKeys = ["lead", "bass", "key", "drums", "pad", "clock", "pod", "arp"]
filledWithSilence parts = map (\x -> addSilence x) parts
addSilence pt = map (\x -> if (Map.member x (pt)) then (x, pt ! x) else (x, silence)) allowedAndNeededKeys
transform x = transformBy 1 x
transformBy _ [] = []
transformBy y [x] = [(show y, snd x)]
transformBy y (x:xs) = (show y, snd x) : (transformBy (y + 1) xs)
Hey @kit-christopher, glad to hear that you give these concepts a chance!
any other ideas?
Hard to tell since I don't recognize the indentations. It it possible for you to add the TC code here in the code block? Do you get an error message? What does it look like? When I evaluate the code from code.tidal, everything works like I expect.
sorry! i put the code into a block above...i just copied and pasted your stuff into an existing tidal session i had open and evaluated every line on its own. here's the error i get when trying to eval the Map portion
Not in scope: `Map.fromList'
No module named `Map' is imported.
Not in scope: `Map.!'
No module named `Map' is imported.
Not in scope: `Map.member'
No module named `Map' is imported
Oh, I didn't realized that I forgot that. You need to evaluate import qualified Data.Map.Strict as Map. I have this added to my BootTidal.hs and will add it this line to the code.tidal file.
This should fix the problem.
wonderful, adding now! thanks @mrreason!
Hi all! I am also interested in this problem, though I've gone about it a little differently than @mrreason.
I like the way chord modifications work in TidalCycles, but with the existing chord utilities, in order to stay in the key, I would need to know if the chord built on, say, the 2nd scale degree should be major or minor (or something else) to keep all the tones in the key. And I'd also need to know what note the 2nd scale degree is -- an easier problem but a non-trivial one (for me, at least). I've become more familiar with answering these questions in a major scale over time, but I hate memorizing and wanted to be able to play around in other modes/scales.
I've been playing with my ideas in a fork. The keyChords function that I wrote builds chords on scale degrees with a given tonic and scale. Here's an example:
d1 $ slow 4 $ keyChords "g4" "major" "1 2 4-i-d 5-ii-d" # s "superfm"
This would play a I ii IV V progression in g major, with the IV being first inversion and the V being second inversion. The -d on those two chords brings them down an octave. I've implemented some other chord modifications to work with this function as well.
One fun thing that wasn't part of my original intention is that the tonic and the scale can be patterned too, which I want to play with a bit more in compositions.
I'm wondering: is anybody working on bringing something like this to version 2.0, or is it out of scope? I'd love for TidalCycles to have more options for composition within a chosen key. I'd be happy to work on upstreaming any of this if people want, or to help if there's other efforts 