Add module for guitars.

music_theory/guitar.py

@@ -0,0 +1,21 @@
+from .scales import CHROMATIC_SCALE
+
+def construct_fretting(tuning, fret_limit=12):
+    """
+    `tuning` is a string describing the notes sounded by the guitar string when
+    played in open. No length restrictions are imposed because, hey, whatever
+    set-up floats your guitar. :)
+    """
+    fretting = []
+
+    for open_note in tuning:
+        string = []
+        open_norm = open_note.upper()
+        initial_index = CHROMATIC_SCALE.index(open_norm)
+
+        for i in range(fret_limit + 1):
+            string.append(CHROMATIC_SCALE[(initial_index + i) % len(CHROMATIC_SCALE)])
+
+        fretting.append(string)
+
+    return fretting

music_theory/tests/guitar_tests.py

@@ -0,0 +1,17 @@
+from ..guitar import construct_fretting
+
+import unittest
+
+class GuitarTests(unittest.TestCase):
+
+    def test_construct_fretting(self):
+        standard_fretting = [
+            ["E", "F", "F#", "G", "G#", "A", "A#", "B", "C", "C#", "D", "D#", "E"],
+            ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A"],
+            ["D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B", "C", "C#", "D"],
+            ["G", "G#", "A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G"],
+            ["B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"],
+            ["E", "F", "F#", "G", "G#", "A", "A#", "B", "C", "C#", "D", "D#", "E"],
+        ]
+
+        self.assertEqual(standard_fretting, construct_fretting("EADGBe"))