음악 이론 관련 링크

Diatonic scale 다이어토닉 스케일 (온음계)
Chromatic scale (반음계)Augmented unison
http://en.wikipedia.org/wiki/Degree_(music)

Diminished fourth
Diminished Fifth = Augmented fourth (Tritone)

http://en.wikipedia.org/wiki/Tonic_(music)
http://en.wikipedia.org/wiki/Subdominant
http://en.wikipedia.org/wiki/Dominant_(music)

http://en.wikipedia.org/wiki/Seventh_chord
http://en.wikipedia.org/wiki/Dominant_seventh_chord
http://en.wikipedia.org/wiki/Major_seventh_chord
http://en.wikipedia.org/wiki/Minor_seventh

http://en.wikipedia.org/wiki/Suspended_chord
Dominant 7th sus 4 같은 것에서 sus가 suspended chord 라는 뜻.

http://en.wikipedia.org/wiki/Circle_of_fifths

http://en.wikipedia.org/wiki/Chord_progression
http://en.wikipedia.org/wiki/Ii-V-I_turnaround
http://en.wikipedia.org/wiki/Pachelbel's_Canon

위키 > Seventh_chord 중에서:
CΔ7(IΔ7) 등.
Major seventh (formally major/major seventh, also maj7, M7, Δ, ⑦, etc.): root, major third, perfect fifth, major seventh

위키 > Subdominant 중에서: