Hey, people !

 

I´m doing a function to extract the complementary set of notes.

For example:

 

1) Specify a set of notes, like a chord, Dm7

 

(setf note-list '(d5 f5 a5 c6))

 

Specify a tonality, like Cmajor or D dorian (same notes)

(expand-tonality '(c5 major))

 

Now, I want a function that gives me all the other available notes from the mode, except the chord tones (the first set of notes).

 

So, this function gives me exactly what I need (for ONE tonality at a time and ONE chord at a time):

 

(let ((rem (expand-tonality '(c5 major)))
      (super (ambitus '(c5 b5) note-list)))
  (loop for i in super
    do (setf rem (remove i rem))
    finally (return rem)))

 

Ok, this give me the right result, I.E., the complementary set of notes of C major in relation to Dm7

=> (e5 g5 b5)

 

The question is simple:

 

How can I do it for a list with many tonalities and many chords. How to do this recursively in nested lists, like

 

(setf note-list '((d5 f5 a5 c6)(eb4 gb4 bb4 db4)(fs4 as4 cs4)))

 

to sucessive tonalities, like:

(expand-tonality '((c5 major) (db4 major) (gb4 major)))

 

Since this WON´T work

 

(let ((rem (ambitus '(c5 b5) (expand-tonality '((c5 major) (db5 major) (gb5 major)))))
      (super (ambitus '(c5 b5) '((d5 f5 a5 c6)(eb4 gb4 bb4 db4)(fs4 as4 cs4)))))
  (loop for i in super
    do (setf rem (remove i rem))
    finally (return rem)))

 

The expected result, if the above worked would be:

 

 ((e5 g5 b5)  (f5 ab5 c5) (gs4 cb5 ds5))

 

Thanks in advance !!

 

Best !

Julio

Loop in the loop:

 

(let ((rem (ambitus '(c5 b5) (expand-tonality '((c5 major) (db5 major) (gb5 major)))))
      (super (ambitus '(c5 b5) '((d5 f5 a5 c6) (eb4 gb4 bb4 db4) (fs4 as4 cs4)))))
  (loop for s in super
    for r in rem
    collect (loop for i in s
              do (setf r (remove i r))
              finally (return r))))

Thanks, Janusz

 

This could implemented as a native function, like

 

FILTER-SET

 

A general function to filter sets out of sets.

 

Best,

Julio

This function FILTER-SET would be interesting in the core set of functions !

Still coming back to this from time to time when working with pcs sets.

Best !

Julio

Here’s one of my functions that I use for that:

;;; FIND-PITCH-COMPLEMENT

;;; ------------------------

(defun find-pitch-complement (omn &key (keep-octaves nil))

"Renvoie le complement de hauteurs d'une expression omn."

(do-verbose ("find-pitch-complement")

(let* ((pch (ambitus '(0 11) (melodize (omn :pitch omn))))

(itg (pitch-to-integer pch))

(cpl (find-complement itg :low 0 :high 11))

(pcpl (integer-to-pitch cpl))

)

(if keep-octaves

(octave-map omn pcpl)

pcpl))))

#| USAGE EXAMPLE

(setf omn1 (length-legato

(gen-filter-euclidean

12

16

7 14

(vector-to-pitch '(c4 c6)(gen-noise 32))

's :seed 34)))

(setf omn2

(make-omn

:pitch (chordize (find-pitch-complement omn1))

:length (length-span (get-span omn1) '((w)))

:velocity '(mf)))

(ps 'gm

:fl (list omn1)

:pg (list omn2)

)

|#

Thanks a lot, Stephane !

All the best !

Julio