

A131803


A binary Major Minor chord substitution: Chord progression start vector {4, 11, 9, 2, 5, 7} Cmajor, Gminor,Fminor,BbMajor,Dbminor, Ebminor.


0



4, 8, 11, 3, 8, 12, 3, 7, 11, 4, 6, 9, 3, 6, 10, 1, 8, 12, 3, 7, 12, 4, 7, 11, 3, 6, 10, 1, 7, 10, 2, 5, 11, 4, 6, 9, 4, 8, 11, 3, 6, 10, 1, 5, 9, 12, 4, 7, 3, 6, 10, 1, 6, 10, 1, 5, 10, 2, 5, 9, 1, 4, 8, 11, 11, 4, 6, 9, 4, 8, 11, 3, 6, 10, 1, 5, 9, 12, 4, 7, 4, 8, 11, 3, 8, 12, 3, 7, 11, 4, 6, 9, 3, 6
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

This substitution sequence is very like a Jazz chord progression in major (even) and minor (odd) chords. I call it a melt down.


LINKS

Table of n, a(n) for n=1..94.


FORMULA

Start vector>{4, 11, 9, 2, 5, 7} 1>{1, 4, 8, 11}, 2>{2, 6, 9, 1}, 3>{3, 6, 10, 1}, 4>{4, 8, 11, 3}, 5>{5, 8, 12, 3}, 6>{6, 10, 1, 5}, 7>{7, 10, 2, 5}, 8>{8, 12, 3, 7}, 9>{9, 12, 4, 7}, 10>{10, 2, 5, 9}, 11>{11, 4, 6, 9}, 12>{12, 4, 7, 11}


MATHEMATICA

s0[i_] := {i, If[i + 4 > 12, i  8, i + 4], If[i + 7 > 12, i  5, i + 7], If[i + 11 > 12, i  1, i + 11]}; s1[i_] := {i, If[i + 3 > 12, i  7, i + 3], If[i + 7 > 12, i  5, i + 7], If[i + 10 > 12, i  2, i + 10]}; s[i_] := If[Mod[i, 2] == 0, s0[i], s1[i]] t[a_] := Flatten[s /@ a]; p[0] = {4, 11, 9, 2, 5, 7}; p[1] = t[p[0]]; p[n_] := t[p[n  1]]; p[3]


CROSSREFS

Cf. A133269, A133270.
Sequence in context: A109445 A316505 A293597 * A133270 A131517 A076689
Adjacent sequences: A131800 A131801 A131802 * A131804 A131805 A131806


KEYWORD

nonn,uned


AUTHOR

Roger L. Bagula, Oct 23 2007


STATUS

approved



