I'd like to know why I can't seem to process this list of chords using the pitch-variation function.

 

Thank you!

 

(setf chords '((h a2a3c4 c4a3a3) (h d4f3g2 f4g3d4) (h e4c4a3 c3a3e4) (h d3a3f4 w f4d4a3) (h e2e3g3 g3e4e4) (h a3f4e4 f2e3a3) (h e4g3b3 b3e3g2) (h a2d3fs2 w fs2a2e2) (h a2e3c4 c4a3e4) (h e4g3b3 b3e3g2) (h f2e3a3 a3f4e4) (h e4e4g3 w g3e3e2) (h d3a3f4 f4d4a3) (h e4c4a3 c3a3e4) (h b2a3d4 d4b3a3) (h a3a3c4 w c4a3a2)))

(pitch-variation 0 1 7 chords
                 :type '? :seed 23)

 

(setf chords '((h a2a3c4 c4a3a3)))

(pitch-variation 0 1 7 chords
                 :type '? :seed 23)

 

The first bar already returns an error.

If you change the duplicate a3 in the second chord it will work. Why two a3 in a chord?

 

On the other hand why not. Shouldn't  throw an error.

with chord-pitch-unique no error.

 

(pitch-variation 0 1 7 (chord-pitch-unique chords)
                 :type '? :seed 23)

Just play around a little with pitch-variation a little, why does it makes no difference in the output what

:type

I choose?

What am I missing?

(setf chords '((h a2a3c4 c4a3a3) (h d4f3g2 f4g3d4)))

(pitch-variation 0 1 4 (chord-pitch-unique chords)
                 :type 'c :seed 23)  
==>((h a3 c4 a2 a3) (h c4 a3 c4 a3) (h g2 f3 d4 f3) (h d4 f4 g3 f4))

(pitch-variation 0 1 4 (chord-pitch-unique chords)
                 :type 'm :seed 23) 
==>((h a3 c4 a2 a3) (h c4 a3 c4 a3) (h g2 f3 d4 f3) (h d4 f4 g3 f4))

(pitch-variation 0 1 4 (chord-pitch-unique chords)
                 :type '? :seed 23) 
==>((h a3 c4 a2 a3) (h c4 a3 c4 a3) (h d4 g2 f3 g2) (h d4 g3 d4 f4))

 

Thanks!

Of course not, step 0 will not return chords.

 

(pitch-variation 6 1 4 (chord-pitch-unique chords) :type 'c)

 

Ok, thanks, I think I don't get what

pitch-variation

does and what the parameters do.

If someone is willing to explain, I would be very greatful, I think I don't have a clue..:-)

 

Thanks!

Wasn't the initial question why this throws an error:

 

(setf chords '((h a2a3c4 c4a3a3) (h d4f3g2 f4g3d4) (h e4c4a3 c3a3e4) (h d3a3f4 w f4d4a3) (h e2e3g3 g3e4e4) (h a3f4e4 f2e3a3) (h e4g3b3 b3e3g2) (h a2d3fs2 w fs2a2e2) (h a2e3c4 c4a3e4) (h e4g3b3 b3e3g2) (h f2e3a3 a3f4e4) (h e4e4g3 w g3e3e2) (h d3a3f4 f4d4a3) (h e4c4a3 c3a3e4) (h b2a3d4 d4b3a3) (h a3a3c4 w c4a3a2)))

 

(pitch-variation 0 1 7 chords    :type '? :seed 23)

 

So why does it throw an error?

When there are no duplicate notes in a chord there is no error.

Are duplicate notes in a chord not allowed? They make no sense, but could have been randomly generated. 

 

I will remove the duplicate notes in a chord before the process. I will add the chord-pitch-unique function into the function.

Will be fixed in the next release.

Thanks everyone, for looking into this and providing a solution. This is a very powerful and versatile function.

Would it be possible to revise the pitch-variation function so that one can use lists of parameter values also for the repeat and step values? I noticed the functions accepts lists only with the size parameter.

 

Thanks again!

Hi Zvony,

 

waiting the revision of pitch-variation function, you could use mapcar function to do that or also OM function gen-process:

 

(setf chords (gen-repeat 4 '((c4e4g4 d4f4a4 g4b4d5))))

(assemble-seq
 (mapcar(lambda(x y z ch)
          (pitch-variation
           x y z ch))
        '(0 2 1 2)
        '(0 1 1 0)
        '(2 3 4 3)
        chords
        )
)
            
(assemble-seq
 (gen-process 
  '(pitch-variation a b c d)
  '((0 2 1 2)(0 1 1 0)(2 3 4 3) chords)
  )
)

Best !

S.

 

Thanks so much, Stephane! This is very helpful.