musician 🎹
Installation
$ gem install musician
The main method of musician is key_change()
key = "G"
chords = ["G", "F#", "Em", "C"]
song = Song.new(key, chords)
song = song.key_change("A") # Change to key of A
p song.chord_names
#=> ["A", "G♯", "F♯m", "D"]There are 3 classes in musician:
Note, Chord, and Song. Chord is inherited from Note
When a Song instance variable is created, the key (a string) and the chords (an array of strings)
become a new object, Chord
# after creating a new instance variable,
p song.chords
# will return an array of objects
# if you just want the chords as an array of strings though,
# the following will return that for you, like in the example code above
p song.chord_namesLooking at the previous example of code,
you can see that song.key returns an object instead of a string
p song.key
#=> #<Chord:0x007fb16102cb90 @name="G", @raw_name="G"... >Here's a look at the Chord class
chord = Chord.new("G#m7")
chord.name
#=> "G♯m7"
chord.sharp?
#=> true
chord.flat?
#=> false
chord.position # Starting from "C", "C" being 0
#=> 8
chord.raw_name
#=> "G♯"
chord.addition
#=> "m7"The sharp?, flat?, and position methods can also be used with the Note class
If you pass a pound sign "#" or a lowercase "b" when creating an instance variable, it will automatically be changed into a sharp "♯" or flat "♭" respectively
sharp_chord = Chord.new("G#")
p sharp_chord.name
#=> "G♯"
flat_chord = Chord.new("Gb")
p flat_chord.name
#=> "G♭"Key change options
When the key_change() method is called, an option can be passed as the second argument.
This determines how the chords of the song are changed.
There are 4 options that can be chosen from
:sharp # This is the default option
:flat
:all_sharp
:all_flatOption 1 (:sharp)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key)
p song.chord_names
#=> ["A", "A♭", "F♯m", "D"]
# Any chord that was originally flat will stay flat if applicable
# In any other case, they will become sharp (Like "F♯m")Option 2 (:flat)
key = "G"
chords = ["G", "F♯", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :flat)
p song.chord_names
#=> ["A", "G♯", "G♭m", "D"]
# Any chord that was originally sharp will stay sharp if applicable
# In any other case, they will become flat (Like "G♭m")Option 3 (:all_sharp)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :all_sharp)
p song.chord_names
#=> ["A", "G♯", "F♯m", "D"]
# All applicable chords will be changed into sharpsOption 4 (:all_flat)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :all_flat)
p song.chord_names
#=> ["A", "A♭", "G♭m", "D"]
# All applicable chords will be changed into flatsSupported chords
The following chords are supported:
# Any of these can be added at the end of a chord or key
# for example: "Am7"
"add2"
"add9"
"dim7"
"dim"
"sus4"
"sus"
"maj7"
"maj"
"m7"
"m"
"aug"
"2"
"6"
"7"
"9"
"11"Pro Tip
When calling song.key_change(key, chords),
The variables key and chords can be passed as either a string or a Chord object
(Make sure chords is an array)
インストール
$ gem install musician
musicianの主要の機能はkey_change()、歌の転調を行うメソッドです。
key = "G"
chords = ["G", "F#", "Em", "C"]
song = Song.new(key, chords)
song = song.key_change("A") # "A"に転調します
p song.chord_names
#=> ["A", "G♯", "F♯m", "D"]musicianでは、３つのクラスが存在しています。
Note、それを継承するChord、そしてSongです。
Songのインスタンス変数が作られる時に、渡されたkey(文字列)とchords(文字列の配列)がChordクラスのインスタンス変数として作られます。
# songのインスタンス変数を作ったら、
p song.chords
# はオブジェクトの配列を返します
# オブジェクトじゃなくて文字列の配列だけが要るなら、
p song.chord_names
# は、上記のコードみたいに文字列の配列を返します。上記のコードで定義されたsongインスタンス変数のキーであるsong.keyを参照すると、オブジェクトが返されることが分かります。
p song.key
#=> #<Chord:0x007fb16102cb90 @name="G", @raw_name="G"... >Chordクラスのメソッド：
chord = Chord.new("G#m7")
chord.name
#=> "G♯m7"
chord.sharp?
#=> true
chord.flat?
#=> false
chord.position # 「C」は０番目です
#=> 8
chord.raw_name
#=> "G♯"
chord.addition
#=> "m7"Noteでは、sharp?, flat?、とpositionが使えます。
新しいNoteやChordを作る時に、パウンド記号「#」がシャープ記号「♯」になり、
小文字の「b」がフラット記号「♭」になります。
sharp_chord = Chord.new("G#")
p sharp_chord.name
#=> "G♯"
flat_chord = Chord.new("Gb")
p flat_chord.name
#=> "G♭"
key_change()のオプション
key_change()の２つ目の引数をオプションとして定義できます。
これは、歌のコードはどんな風に転調されるかを決めます。
尚、optionを省略しても大丈夫です。
４つのオプションがあります：
:sharp # デフォルトのオプション
:flat
:all_sharp
:all_flatオプション１ (:sharp)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :sharp)
p song.chord_names
#=> ["A", "A♭", "F♯m", "D"]
# そもそもフラットであったコードはそのままフラットに変換されます
# それ以外のコードはシャープに変換されます（「F♯m」みたいに）オプション２ (:flat)
key = "G"
chords = ["G", "F♯", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :flat)
p song.chord_names
#=> ["A", "G♯", "G♭m", "D"]
# そもそもシャープであったコードはそのままシャープに変換されます
# それ以外のコードはフラットに変換されます（「G♭m」みたいに）オプション３ (:all_sharp)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :all_sharp)
p song.chord_names
#=> ["A", "G♯", "F♯m", "D"]
# 対象となるコードは全部シャープに変換されますオプション４ (:all_flat)
key = "G"
chords = ["G", "Gb", "Em", "C"]
song = Song.new(key, chords)
new_key = "A"
song = song.key_change(new_key, :all_flat)
p song.chord_names
#=> ["A", "A♭", "G♭m", "D"]
# 対象となるコードは全部フラットに変換されます使用可能なコード
下記のコードは使用できます：
# コードやキーの語尾として追加できます
# 例えば: "Am7"
"add2"
"add9"
"dim7"
"dim"
"sus4"
"sus"
"maj7"
"maj"
"m7"
"m"
"aug"
"2"
"6"
"7"
"9"
"11"裏技
song.key_change(key, chords)を呼ぶ時に、
変数のkeyとchordsは文字列かChordのインスタンス変数、どちらでも構いません
（chordsは配列でなければなりません）