Scale:circle_of_5ths_rotate & ChordBuilder:extend

chord.lua

@@ -336,6 +336,20 @@ function ChordBuilder:clone()
   return b
 end
 
+-- extensions is a table of 4 elements, false or true
+-- the first element is the seventh,
+-- the second is the ninth,
+-- the third is the eleventh,
+-- the fourth is the thirteenth
+function ChordBuilder:extend(extensions)
+  local b = self:clone()
+  b.seventh = extensions[1]
+  b.ninth = extensions[2]
+  b.eleventh = extensions[3]
+  b.thirteenth = extensions[4]
+  return b
+end
+
 function ChordBuilder:withSeventh()
   local b = self:clone()
   b.seventh = true

scale.lua

@@ -106,6 +106,22 @@ function Scale:to_the_right_on_circle_of_5ths(iterations)
     :to_the_right_on_circle_of_5ths(iterations -1)
 end
 
+--[[
+  Warning: only works for ionian scales
+]]
+function Scale:circle_of_5ths_rotate(iterations)
+  if(iterations == 0) then
+    return self
+  elseif(iterations < 0) then
+    return self:to_the_left_on_circle_of_5ths(-iterations)
+  elseif(iterations > 0) then
+    return self:to_the_right_on_circle_of_5ths(iterations)
+  else
+    return "Error"
+  end
+end
+
+
 --[[
   Returns a new scale based on self, rotated from note_offset
   note_offset: