Before applying the 24:17:13:7:3 sequence of the previous post, I though, that I could check all Fibonacci sequences modulo 2 to 12 (period(12)=24) and see if some are interesting for my goal.
The period of a Fibonacci sequence is called Pisano period and —to my knowledge— there is not a formula with ()+-*/^ that could give them as a function of the modulo m. Thus I wrote a small Python script that does this:
def my_zeros(n):
result = []
for i in range(n):
result.append(0)
return result
for modulo in range(2,13):
print "modulo =",modulo
max = modulo**2
fibonacci = my_zeros(max)
fibonacci[0] = 0
fibonacci[1] = 1
j = 2
for j in range(2, max):
fibonacci[j] = (fibonacci[j-1] + fibonacci[j-2]) % modulo
# the 2 last numbers x=F_(n-1) y=F_n of the period
# must satisfy the following (for modulo m):
# x + y = 0 mod m
# y + 0 = 1 mod m
# because 0 and 1 should be the next numbers.
# Thus (x,y) = (m-1, 1).
if fibonacci[j] == 1:
if fibonacci[j-1] == modulo - 1:
per = j + 1
break
print fibonacci[0:per]
print "period =", per
print
The output is very interesting:
modulo = 2
[0, 1, 1]
period = 3
modulo = 3
[0, 1, 1, 2, 0, 2, 2, 1]
period = 8
modulo = 4
[0, 1, 1, 2, 3, 1]
period = 6
modulo = 5
[0, 1, 1, 2, 3, 0, 3, 3, 1, 4, 0, 4, 4, 3, 2, 0, 2, 2, 4, 1]
period = 20
modulo = 6
[0, 1, 1, 2, 3, 5, 2, 1, 3, 4, 1, 5, 0, 5, 5, 4, 3, 1, 4, 5, 3, 2, 5, 1]
period = 24
modulo = 7
[0, 1, 1, 2, 3, 5, 1, 6, 0, 6, 6, 5, 4, 2, 6, 1]
period = 16
modulo = 8
[0, 1, 1, 2, 3, 5, 0, 5, 5, 2, 7, 1]
period = 12
modulo = 9
[0, 1, 1, 2, 3, 5, 8, 4, 3, 7, 1, 8, 0, 8, 8, 7, 6, 4, 1, 5, 6, 2, 8, 1]
period = 24
modulo = 10
[0, 1, 1, 2, 3, 5, 8, 3, 1, 4, 5, 9, 4, 3, 7, 0, 7, 7, 4, 1, 5, 6, 1, 7, 8, 5,
3, 8, 1, 9, 0, 9, 9, 8, 7, 5, 2, 7, 9, 6, 5, 1, 6, 7, 3, 0, 3, 3, 6, 9, 5, 4,
9, 3, 2, 5, 7, 2, 9, 1]
period = 60
modulo = 11
[0, 1, 1, 2, 3, 5, 8, 2, 10, 1]
period = 10
modulo = 12
[0, 1, 1, 2, 3, 5, 8, 1, 9, 10, 7, 5, 0, 5, 5, 10, 3, 1, 4, 5, 9, 2, 11, 1]
period = 24
Now the idea is the following: let all sequences represent divisions of the octave by the respective modulo (e.g. m=12: semitones, m=11: 1/11 of the octave etc) and stretch them equidistant in order to fill the same duration. Then select the ones that are going to sound at the given position (filtering). Allow rhythmical and pitch deviations. The whole piece is in forte.
About the words: I decided not to use a poem. I think 2 arts at the same time is a bit too much for my taste. Music alone should suffice.