Just a framework for musical expression in Common Lisp with a focus on music theory!
Totally building it from scratch, there's lots to do and a lot is missing/broken.
It currently uses SBCL timers for queuing real time midi events, so it's SBCL dependant.
See examples/nyan.lisp for an example of a song.
You can designate pitch classes with symbols:
'c 'c♯ 'f♭ 'g♯♯♯
And actual notes with octaves as well:
'c5 'a♭♭7
You can designate intervals with symbols:
'p5 'maj7 2dim2 (doubly diminished second)
You can designate harmonies like this:
'ii 'IVdom9 'vmin42♯5
You can make a harmony like this:
(harmony 'I7/V)
;; => (D F♯ A C)
(harmony 'IVmaj43)
;; => (C E F A)
You can get a scale like this:
(scale (key 'g-phrygian))
;; => (G A♭ B♭ C D E♭ F)
You can designate scale degrees with either numbers, names or solfège syllables:
'(do re 3 4 dominant submediant)
You can realize scale degrees and pitch class like this:
(realize '(do re 3 4 dominant submediant))
;; => (C4 E4 G4 F4 B4 A4 B4 G2)
You can also nest them:
(realize '(do re mi (fa sol la) ti do))
;;; => (C4 D4 E4 (F4 G4 A4) B4 C5)
And indicate octave displacements and rests like this:
(realize '(mi fa > mi fa > mi r < < < < re r))
;; => (E4 F4 E5 F5 E6 R D2 R)
You can realize harmonic progressions in a simple way like this:
(realize (harmony '(I IV64 V43 I6)))
;; => ((C4 E4 G4) (C4 F4 A4) (D4 F4 G4 B4) (E4 G4 C5))
You can get the interval between notes like this:
(difference (note 'g5) (note 'f6))
;; => MIN7
You can get the note or pitch class an interval above or below another like this:
(above (note 'a♭4) (interval 'p8))
;; => A♭5
(below (pitch-class 'd) (interval 'aug2))
;; => C♭
You can add intervals like this:
(sum (interval 'maj6) (interval 'maj3)
;; => AUG8
Why not stack 100 perfect fifths together and see what you get?
(loop
:with i = (interval 'p1)
:repeat 100
:do (setf i (sum i (interval 'p5)))
:finally (return i))
;; => 14AUG401
You can get relative or parallel keys like this:
(parallel (key 'f-major) 'minor)
;; => F-MINOR
(relative (key 'f♯-minor) 'mixolydian)
;; => E-MIXOLYDIAN
You can make a sequence like this:
(seq '(> sol la < ri mi re me re do do re))
You can make a chord like this:
(chord '(do mi sol te))
You can designate rhythms using divisions of beats like this:
;; "one and two and three and four
(2 2 2 2 2 2 1 2 2 2 2 2 2 1) ;; twinkle twinkle
;; "one-ee uh ee-and three four"
(4 2 2 4 2 1 1) ;; mario theme opening rhythm
And you can give rhythm to a sequence like this:
(seq '(> sol la < ri mi re me re do do re)
'(2 2 4 2 4 4 4 2 2 2))
You can play things with live midi using portmidi like this:
(play (seq '(> sol la < ri mi re me re do do re)
'(2 2 4 2 4 4 4 2 2 2)))
Which implicitely wraps the expression in event first:
(event (seq '(> sol la < ri mi re me re do do re)
'(2 2 4 2 4 4 4 2 2 2)))
;; => (G4@0s-1/4s A4@1/4s-1/2s D♯4@1/2s-5/8s E4@5/8s-7/8s D4@7/8s-1s E♭4@1s-9/8s D4@9/8s-5/4s C4@5/4s-3/2s C4@3/2s-7/4s D4@7/4s-2s)
Which turns the expression into a list of timed events.