Set version to 0.1 and update README (#11)

Project.toml

@@ -1,14 +1,9 @@
 name = "MusicTheory"
 uuid = "564e61e1-4667-41b2-a4a2-754a0240c775"
 authors = ["David Sanders <[email protected]> and contributors"]
-version = "1.0.0-DEV"
+version = "0.1"
 
 [deps]
-ColorTypes = "3da002f7-5984-5a60-b8a6-cbb66c0b333f"
-Colors = "5ae59095-9a9b-59fe-a467-6f913c188581"
-GeometryTypes = "4d00f742-c7ba-57c2-abde-4428a4b178cb"
-Luxor = "ae8d54c2-7ccd-5906-9d76-62fc9837b5bc"
-Parameters = "d96e819e-fc66-5662-9728-84c9c7592b0a"
 
 [compat]
 julia = "1"

README.md

@@ -2,22 +2,22 @@
 
 [![Build Status](https://github.com/dpsanders/MusicTheory.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/dpsanders/MusicTheory.jl/actions/workflows/CI.yml?query=branch%3Amain)
 
-A Julia package for the basics of ("Western") music theory.
-(Currently) everything is based on semitones.
+The goal of this package is to provide a Julian interface for representing
+the objects and structures in ("Western") music theory (based on semitones).
 
 ## Contents
 - Pitches with scientific notation, e.g. C4 for middle C
 - Intervals
 - Scales
-- Chords
 - Notes and rests with durations
+- Chords
 
 ## Pitches
 Pitch names are exported in the `MusicTheory.PitchNames` submodule.
 
 Specifying just the name of a pitch gives a `PitchClass`, representing all notes of that
 pitch, e.g.
-```
+```jl
 julia> C♯
 C♯
 
@@ -26,28 +26,28 @@ PitchClass
 ```
 
 Indexing gives a pitch with a specific octave, e.g.
-```
+```jl
 julia> C♯[4]
 C♯₄
 ```
 
 ## Intervals
 The `Interval` type computes the interval between two pitches:
-```
+```jl
 julia> Interval(C[4], E[4])
 Major 3rd
 ```
 
 ## Scales
 General scales are supported; they are specified as a sequence of intervals dividing up an
 octave, e.g.
-```
+```jl
 julia> show(major_scale)
 Interval[Major 2nd, Major 2nd, Minor 2nd, Major 2nd, Major 2nd, Major 2nd, Minor 2nd]
 ```
 
 The `Scale` type is a standard Julia iterator over the scale:
-```
+```jl
 julia> scale = Scale(C[4], major_scale)
 Scale{Pitch}(C₄, Dict{PitchClass, Interval}(C => Major 2nd, E => Minor 2nd, B => Minor 2nd, F => Major 2nd, D => Major 2nd, G => Major 2nd, A => Major 2nd))
 
@@ -60,14 +60,49 @@ Pitch[C₄, D₄, E₄, F₄, G₄, A₄, B₄, C₅]
 ## Notes
 Notes have a pitch and a duration, which is a rational number, e.g. `1 // 4` for a
 quarter note (crotchet). Rests are specified using `rest`, e.g.
-```
+```jl
 julia> notes = [C[5] / 4, rest / 8, D[5] / 8]
 3-element Vector{Note}:
  Note(C₅, 1//4)
  Note(MusicTheory.Rest(), 1//8)
  Note(D₅, 1//8)
 ```
 
+## Example
+A motivating example for writing this package was to be able to do the following types of
+computations.
+
+When playing the violin, it's common to have a scale in thirds: take a scale and for each
+scale tone, play the note two steps above it in the scale at the same time.
+
+Question: Which combinations of half/whole steps and pairs of major/minor thirds
+are possible?
+
+Answer:
+```jl
+julia> scale = Scale(C[4], major_scale)
+
+julia> notes = Base.Iterators.take(scale, 10) |> collect
+
+julia> thirds = zip(notes, notes[3:end]) |> collect
+
+julia> thirds_intervals = Interval.(thirds)
+
+julia> note_intervals = Interval.(zip(notes, notes[2:end]))
+
+julia> combinations =
+        [ (note_intervals[i], thirds_intervals[i], thirds_intervals[i+1])
+            for i in 1:(length(thirds)-1)
+        ]
+
+julia> result = unique(combinations)
+4-element Vector{Tuple{Interval, Interval, Interval}}:
+ (Major 2nd, Major 3rd, Minor 3rd)
+ (Major 2nd, Minor 3rd, Minor 3rd)
+ (Minor 2nd, Minor 3rd, Major 3rd)
+ (Major 2nd, Major 3rd, Major 3rd)
+```
+
 ## Author
 
 Copyright David P. Sanders, 2024