[patch] Parse "minor" and "natural_minor" as the Aeolian mode

Semantics.Music/Mode.cs

@@ -10,15 +10,18 @@
 /// </summary>
 public sealed record Mode
 {
+	// Named once because the shape table, its aliases and the static instance all refer to it.
+	private const string AeolianName = "aeolian";
+
 	private static readonly Dictionary<string, int[]> Shapes = new(StringComparer.OrdinalIgnoreCase)
 	{
 		// Diatonic modes.
 		["major"] = [0, 2, 4, 5, 7, 9, 11],
 		["dorian"] = [0, 2, 3, 5, 7, 9, 10],
 		["phrygian"] = [0, 1, 3, 5, 7, 8, 10],
 		["lydian"] = [0, 2, 4, 6, 7, 9, 11],
 		["mixolydian"] = [0, 2, 4, 5, 7, 9, 10],
-		["aeolian"] = [0, 2, 3, 5, 7, 8, 10],
+		[AeolianName] = [0, 2, 3, 5, 7, 8, 10],
 		["locrian"] = [0, 1, 3, 5, 6, 8, 10],
 
 		// Minor scales.
@@ -59,6 +62,8 @@
 	private static readonly Dictionary<string, string> Aliases = new(StringComparer.OrdinalIgnoreCase)
 	{
 		["ionian"] = "major",
+		["minor"] = AeolianName,
+		["natural_minor"] = AeolianName,
 	};
 
 	/// <summary>Gets the canonical lower-case name of the mode.</summary>
@@ -89,7 +94,7 @@
 	public static Mode Mixolydian => new() { Name = "mixolydian" };
 
 	/// <summary>The Aeolian (natural minor) mode.</summary>
-	public static Mode Aeolian => new() { Name = "aeolian" };
+	public static Mode Aeolian => new() { Name = AeolianName };
 
 	/// <summary>The Locrian mode.</summary>
 	public static Mode Locrian => new() { Name = "locrian" };
@@ -174,7 +179,7 @@
 	}
 
 	/// <summary>Tries to parse a mode by name, case-insensitively.</summary>
-	/// <remarks>An alias such as "ionian" parses to its canonical mode (<see cref="Major"/>).</remarks>
+	/// <remarks>An alias parses to its canonical mode: "ionian" to <see cref="Major"/>, and "minor" or "natural_minor" to <see cref="Aeolian"/>.</remarks>
 	/// <param name="name">The mode name.</param>
 	/// <param name="result">The matching mode, or null on failure.</param>
 	/// <returns><see langword="true"/> when the name is a known mode.</returns>

Semantics.Test/Music/KeyTests.cs

@@ -103,6 +103,15 @@ public void Parse_IonianSpelling_IsTheSameKeyAsMajor()
 		Assert.AreEqual(CMajor, Key.Parse("C ionian"));
 	}
 
+	[TestMethod]
+	public void Parse_MinorSpelling_IsTheSameKeyAsAeolian()
+	{
+		Key aMinor = Key.Create(PitchClass.Create(NoteLetter.A, Accidental.Natural), Mode.Aeolian);
+		Assert.AreEqual(aMinor, Key.Parse("A minor"));
+		Assert.IsTrue(Key.TryParse("A minor", out Key? parsed));
+		Assert.AreEqual("A aeolian", parsed!.ToString());
+	}
+
 	[TestMethod]
 	public void TryParseFailsOnUnknownMode()
 	{

Semantics.Test/Music/ModeTests.cs

@@ -46,6 +46,17 @@ public void TryParse_IonianAlias_EqualsMajor()
 		Assert.AreEqual(Mode.Major, result);
 	}
 
+	[TestMethod]
+	[DataRow("minor")]
+	[DataRow("Minor")]
+	[DataRow("natural_minor")]
+	public void Parse_MinorAlias_EqualsAeolian(string name)
+	{
+		Mode parsed = Mode.Parse(name);
+		Assert.AreEqual(Mode.Aeolian, parsed);
+		Assert.AreEqual("aeolian", parsed.ToString());
+	}
+
 	[TestMethod]
 	public void Parse_RejectsUnknown()
 	{