Merge pull request #1230 from tidalcycles/voicings-doc

understand voicings page

website/src/config.ts

@@ -100,6 +100,7 @@ export const SIDEBAR: Sidebar = {
       { text: 'Coding syntax', link: 'learn/code' },
       { text: 'Pitch', link: 'understand/pitch' },
       { text: 'Cycles', link: 'understand/cycles' },
+      { text: 'Voicings', link: 'understand/voicings' },
       { text: 'Pattern Alignment', link: 'technical-manual/alignment' },
       { text: 'Strudel vs Tidal', link: 'learn/strudel-vs-tidal' },
     ],

website/src/pages/understand/voicings.mdx

@@ -0,0 +1,325 @@
+---
+title: Understanding Chord Voicings
+layout: ../../layouts/MainLayout.astro
+---
+
+import { MiniRepl } from '../../docs/MiniRepl';
+import { PitchSlider } from '../../components/PitchSlider';
+import Box from '@components/Box.astro';
+
+# Understanding Chords and Voicings
+
+Let's dig deeper into how chords and voicings work in strudel.
+I'll try to keep theory jargon to a minimum, so hopefully this is approachable for anyone interested.
+
+## What is a chord
+
+Playing more than one note at a time is generally called a `chord`. Here's an example:
+
+<MiniRepl client:visible tune={`note("<[c3,eb3,g3] [f3,a3,c4]>").room(.5)`} />
+
+Here's the same with midi numbers:
+
+<MiniRepl client:visible tune={`note("<[48,51,55] [53,57,60]>").room(.5)`} />
+
+Here, we have two 3-note chords played in a loop.
+You could already stop here and write chords in this style, which is totally fine and gives you control over individual notes.
+One downside is that it can be difficult to find good sounding chords and maybe you're yearning for a way to organize chords in some other way.
+
+## Labeling Chords
+
+Chords are typically given different labels depending on the relationship of the notes within.
+In the number example above, we have `48,51,55` and `53,57,60`.
+
+To analyze the relationship of those notes, they are typically compared to some `root`, which is often the lowest note.
+In our case, the `roots` would be `48` (= `c3`) and `53` (= `f3`).
+We can express the same chords relative to those `roots` like this:
+
+<MiniRepl client:visible tune={`note("<[0,3,7] [0,4,7]>".add("<48 53>")).room(.5)`} />
+
+Now within each chord, each number represents the distance from the root.
+A distance between pitches is typically called `interval`, but let's stick to distance for now.
+
+Now we can see that our 2 chords are actually quite similar, as the only difference is the middle note (and the root of course).
+They are part of a group of chords called `triads` which are chords with 3 notes.
+
+### Triads
+
+These 4 shapes are the most common types of `triads` you will encounter:
+
+| shape | label      |
+| ----- | ---------- |
+| 0,4,7 | major      |
+| 0,3,7 | minor      |
+| 0,3,6 | diminished |
+| 0,4,8 | augmented  |
+
+Here they are in succession:
+
+<MiniRepl
+  client:visible
+  tune={`note("<[0,4,7] [0,3,7] [0,3,6] [0,4,8]>".add("60"))
+.room(.5)._pitchwheel()`}
+/>
+
+Many types of music often only use minor and major chords, so we already have the knowledge to accompany songs. Here's one:
+
+<MiniRepl
+  client:visible
+  tune={`
+note(\`<
+[0,3,7] [0,4,7] [0,4,7] [0,4,7]
+[0,3,7] [0,4,7] [0,3,7] [0,4,7]
+>\`.add(\`<
+a c d f
+a e a e
+>\`)).room(.5)`}
+/>
+
+These are the chords for "The House of the Rising Sun" by The Animals.
+So far, it doesn't sound too exciting, but at least it's recognizable.
+
+## Voicings
+
+A `voicing` is one of many ways a certain chord shape can be arranged.
+The term comes from choral music, where chords can be sung in different ways by assigning different notes to each voice.
+For example we could add 12 semitones to one or more notes in the chord:
+
+<MiniRepl
+  client:visible
+  tune={`note("<[0,3,7] [12,3,7] [12,15,7] [12,15,19]>".add("48"))
+.room(.5)`}
+/>
+
+Notes that are 12 semitone steps apart (= 1 `octave`) are considered to be equal in a harmonic sense, which is why they get the same note letter.
+Here's the same example with note letters:
+
+<MiniRepl
+  client:visible
+  tune={`note("<[c3,eb3,g3] [c4,eb3,g3] [c4,eb4,g3] [c4,eb4,g4]>")
+.room(.5)`}
+/>
+
+These types of voicings are also called `inversions`. There are many other ways we could `voice` this minor chord:
+
+<MiniRepl
+  client:visible
+  tune={`note("<[0,3,7,12] [0,15,24] [0,3,12]>".add("48"))
+.room(.5)`}
+/>
+
+Here we are changing the flavour of the chord slightly by
+
+1. doubling notes 12 steps higher,
+2. using very wide distances
+3. omitting notes
+
+## Voice Leading
+
+When we want to meaningfully connect chords in a sequence, the chosen voicings affect the way each chord transitions to the next.
+Let's revisit "The House of the Rising Sun", this time using our newly acquired voicing techniques:
+
+<MiniRepl
+  client:visible
+  tune={`note(\`<
+[0,3,7] [7,12,16] [0,7,16] [4,7,12]
+[0,3,7] [4,7,12] [0,3,7] [4,7,12]
+>\`.add(\`<
+a c d f
+a e a e
+>\`)).room(.5)`}
+  punchcard
+/>
+
+These voicings make the chords sound more connected and less jumpy, compared to the earlier version, which didn't focus on voicing.
+The way chords interact is also called `voice leading`, reminiscent of how an
+individual choir voice would move through a sequence of chords.
+
+For example, try singing the top voice in the above example. Then try the same
+on the example not focusing on voice leading. Which one's easier?
+
+Naturally, there are many ways a progression of chords could be voiced and there is no definitive right or wrong.
+
+## Chord Symbols
+
+Musicians playing chord-based music often use a `lead sheet`, which is a simplified notation for a piece of music.
+These sheets condense the essential elements, such as chords, into symbols that make the music easy to read and follow.
+For example, a lead sheet for "The House of the Rising Sun" might include chords written like this:
+
+```
+Am | C | D  | F
+Am | E | Am | E
+```
+
+Here, each symbol consists of the `root` of the chord and optionally an `m` to signal it's a minor chord (just the root note means it's major).
+We could mirror that notation in strudel using the `pick` function:
+
+<MiniRepl
+  client:visible
+  tune={`"<Am C D F Am E Am E>"
+  .pick({
+    Am: "57,60,64",
+    C: "55,60,64",
+    D: "50,57,66",
+    F: "57,60,65",
+    E: "56,59,64",
+  })
+  .note().room(.5)`}
+  punchcard
+/>
+
+## The voicing function
+
+Coming up with good sounding voicings that connect well can be a difficult and time consuming process.
+The `chord` and `voicing` functions can be used to automate that:
+
+<MiniRepl client:visible tune={`chord("<Am C D F Am E Am E>").voicing().room(.5)`} punchcard />
+
+Here we're also using chord symbols but the voicings will be automatically generated with smooth `voice leading`, minimizing jumps.
+It is inspired by the way a piano or guitar player would pick chords to accompany a song.
+
+## Voicing Dictionaries
+
+The voicing function internally uses so called `voicing dictionaries`, which can also be customized:
+
+<MiniRepl
+  client:visible
+  tune={`addVoicings('house', {
+  '': ['7 12 16', '0 7 16', '4 7 12'],
+  'm': ['0 3 7']
+})
+chord("<Am C D F Am E Am E>")
+  .dict('house').anchor(66)
+  .voicing().room(.5)`}
+  punchcard
+/>
+
+In a `voicing dictionary`, each chord symbol is assigned one or more voicings.
+The `voicing` function then picks the voicing that is closest to the `anchor` (defaults to `c5`).
+
+The handy thing about this approach is that a `voicing dictionary` can be used to play any chord progression with automated voice leading!
+
+## The default dictionary
+
+When using the default dictionary, you can use these chord symbols:
+
+```
+2 5 6 7 9 11 13 69 add9
+o h sus ^ - ^7 -7 7sus
+h7 o7 ^9 ^13 ^7#11 ^9#11
+^7#5 -6 -69 -^7 -^9 -9
+-add9 -11 -7b5 h9 -b6 -#5
+7b9 7#9 7#11 7b5 7#5 9#11
+9b5 9#5 7b13 7#9#5 7#9b5
+7#9#11 7b9#11 7b9b5 7b9#5
+7b9#9 7b9b13 7alt 13#11
+13b9 13#9 7b9sus 7susadd3
+9sus 13sus 7b13sus
+aug M m M7 m7 M9 M13
+M7#11 M9#11 M7#5 m6 m69
+m^7 -M7 m^9 -M9 m9 madd9
+m11 m7b5 mb6 m#5 mM7 mM9
+```
+
+The available chords and the format is very much inspired by [ireal pro chords](https://technimo.helpshift.com/hc/en/3-ireal-pro/faq/88-chord-symbols-used-in-ireal-pro/).
+Some symbols are synonymous:
+
+- "-" is the same as "m", for example C-7 = Cm7
+- "^" is the same as "M", for example C^7 = CM7
+- "+" is the same as "aug"
+
+You can decide which ones you prefer. There is no international standard for these symbols.
+To get a full chord, the symbols have to be prefixed with a root pitch, e.g. D7#11 is the 7#11 chord relative to the pitch D.
+
+Here are all possible chords with root C:
+
+<MiniRepl
+  client:visible
+  tune={`chord(\`<
+C2 C5 C6 C7 C9 C11 C13 C69
+Cadd9 Co Ch Csus C^ C- C^7 
+C-7 C7sus Ch7 Co7 C^9 C^13 
+C^7#11 C^9#11 C^7#5 C-6 C-69 
+C-^7 C-^9 C-9 C-add9 C-11 
+C-7b5 Ch9 C-b6 C-#5 C7b9 
+C7#9 C7#11 C7b5 C7#5 C9#11 
+C9b5 C9#5 C7b13 C7#9#5 C7#9b5 
+C7#9#11 C7b9#11 C7b9b5 C7b9#5 
+C7b9#9 C7b9b13 C7alt C13#11 
+C13b9 C13#9 C7b9sus C7susadd3 
+C9sus C13sus C7b13sus C Caug 
+CM Cm CM7 Cm7 CM9 CM13 CM7#11 
+CM9#11 CM7#5 Cm6 Cm69 Cm^7 
+C-M7 Cm^9 C-M9 Cm9 Cmadd9 
+Cm11 Cm7b5 Cmb6 Cm#5
+>\`).voicing().room(.5)`}
+  punchcard
+/>
+
+Note that the default dictionary contains multiple ways (= `voicings`) to play each chord symbol.
+By default, the `voicing` function tries to minimize jumps.
+You can alter the picked voicings in various ways, which are now explained in further detail:
+
+## anchor
+
+The `anchor` is a note that is used to align the voicings to:
+
+<MiniRepl client:visible tune={`anchor("<c4 g4 c5 g5>").chord("C").voicing().room(.5)`} punchcard />
+
+By default, the anchor is the highest possible note the voicing can contain.
+When deciding which voicing of the dictionary to pick for a certain chord, the voicing with a top note closest to the anchor wins.
+
+Note that the anchors in the above example match up with the top notes in the pianoroll.
+Like `note`, anchor accepts either midi numbers or note names.
+
+## mode
+
+With `mode`, you can change the way the voicing relates to the `anchor`:
+
+<MiniRepl
+  client:visible
+  tune={`mode("<below above duck root>").chord("C").anchor("c5").voicing().room(.5)`}
+  punchcard
+/>
+
+The modes are:
+
+- `below`: the top note of the voicing is lower than or equal to the anchor (default)
+- `above`: the bottom note of the voicing is higher than or equal to the anchor
+- `duck`: the top note of the voicing is lower than the anchor
+- `root`: the bottom note of the voicing is always the root note closest to the anchor
+
+The `anchor` can also be set from within the `mode` function:
+
+<MiniRepl client:visible tune={`mode("<below above duck root>:c5").chord("C").voicing().room(.5)`} punchcard />
+
+## n
+
+The `n` control can be used with `voicing` to select individual notes:
+
+<MiniRepl
+  client:visible
+  tune={`n("0 3 1 2").chord("<C <Fm Db>>").voicing()
+.clip("4 3 2 1").room(.5)`}
+  punchcard
+/>
+
+## Example
+
+Here's an example of a Jazz Blues in F:
+
+<MiniRepl
+  client:visible
+  tune={`let chords = chord(\`<
+F7 Bb7 F7 [Cm7 F7]
+Bb7 Bo F7 [Am7 D7]
+Gm7 C7 [F7 D7] [Gm7 C7]
+>\`)
+$: n("7 8 [10 9] 8").set(chords).voicing().dec(.2)
+$: chords.struct("- x - x").voicing().room(.5)
+$: n("0 - 1 -").set(chords).mode("root:g2").voicing()
+`}
+  punchcard
+/>
+
+The chords are reused for melody, chords and bassline of the tune.