diff --git a/Parser/Music/IMusicParser.cs b/Parser/Music/IMusicParser.cs
index 53a1d8d..d6e6f9c 100644
--- a/Parser/Music/IMusicParser.cs
+++ b/Parser/Music/IMusicParser.cs
@@ -11,40 +11,41 @@
 
 using Irony.Parsing;
 
-using PGSoftwareSolutions.PGIrony;
-
 namespace PGSoftwareSolutions.Music {
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 	public interface IMusicParser<T>  {
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		T Parse(string music);
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		T Parse(TextReader reader);
 	}
-    /// <summary>TODO</summary>
+	/// <summary>Note types.</summary>
+	/// <remarks>
+	/// Note length can be calculated as Math.Pow(2,-Value).
+	/// </remarks>
 	public enum NoteType {
-    /// <summary>TODO</summary>
+		/// <summary>A quadruple whole note.</summary>
 		Longa			= -2,
-    /// <summary>TODO</summary>
+		/// <summary>A double whole note.</summary>
 		Breve			= -1,
-    /// <summary>TODO</summary>
+		/// <summary>A whole note.</summary>
 		SemiBreve,
-    /// <summary>TODO</summary>
+		/// <summary>A half note.</summary>
 		Minim,
-    /// <summary>TODO</summary>
+		/// <summary>A quarter note.</summary>
 		Crotchet,
-    /// <summary>TODO</summary>
+		/// <summary>An Eighth note.</summary>
 		Quaver,
-    /// <summary>TODO</summary>
+		/// <summary>A 16th note.</summary>
 		SemiQuaver,
-    /// <summary>TODO</summary>
+		/// <summary>A 32nd Note.</summary>
 		DemiSemiQuaver,
-    /// <summary>TODO</summary>
+		/// <summary>A 64th note.</summary>
 		HemiDemiSemiQuaver
 	}
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 	public static class NoteTypeExtensions {
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static NoteType GetNoteType (this NoteType type, Int16 length) {
 			var i = (int)Math.Floor(Math.Log(length,2));
 			var n = (NoteType)(i);
@@ -54,13 +55,13 @@ public static NoteType GetNoteType (this NoteType type, Int16 length) {
 		}
 	}
 
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 	public interface IPitch {
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		PianoKey		PianoKey		{ get; }
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		NoteLetter	NoteLetter	{ get; }
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		SharpFlat	SharpFlat	{ get; }
 	}
 
@@ -68,68 +69,72 @@ public interface IPitch {
 	public enum Octave { _0, _1, _2, _3, _4, _5, _6, _7, _8 }
 	#pragma warning restore
 
-    /// <summary>Play styles</summary>
-    public struct Style  {
-        /// <summary>Legato</summary>
-        public static Style L => new Style(_enum.L, "Legato",   0.950F);
-        /// <summary>Normal</summary>
-        public static Style N => new Style(_enum.N, "Normal",   0.875F);
-        /// <summary>Staccato</summary>
-        public static Style S => new Style(_enum.S, "Staccato", 0.750F);
+	/// <summary>Play styles</summary>
+	public struct Style  {
+		/// <summary>Legato</summary>
+		public static Style L => new Style(_enum.L, "Legato",   0.950F);
+		/// <summary>Normal</summary>
+		public static Style N => new Style(_enum.N, "Normal",   0.875F);
+		/// <summary>Staccato</summary>
+		public static Style S => new Style(_enum.S, "Staccato", 0.750F);
 
-        /// <summary>TODO</summary>
-        public static Style ConvertValue(ParsingContext c, string s) =>
-            _values[(int)(System.Enum.Parse(typeof(_enum), s.ToUpper()))];
+		/// <summary>TODO</summary>
+		public static Style ConvertValue(ParsingContext c, string s) =>
+			_values[(int)(System.Enum.Parse(typeof(_enum), s.ToUpper()))];
 
-        private enum _enum {L,N,S};
-        private static IList<Style> _values = new List<Style> { L, N, S };
+		private enum _enum {L,N,S};
+		private static IList<Style> _values = new List<Style> { L, N, S };
 
-        private Style(_enum value, string name, double factor) :this() {
-            _value  = (int)value;
-            _name   = name;
-            _factor = factor;
-        }
-        /// <summary>TODO</summary>
-        public int    Value  { get { return _value;  } } readonly int    _value;
-        /// <summary>TODO</summary>
-        public string Name   { get { return _name;   } } readonly string _name;
-        /// <summary>TODO</summary>
-        public double Factor { get { return _factor; } } readonly double _factor;
+		private Style(_enum value, string name, double factor) :this() {
+			_value  = (int)value;
+			_name   = name;
+			_factor = factor;
+		}
+		/// <summary>TODO</summary>
+		public int    Value  { get { return _value;  } } readonly int    _value;
+		/// <summary>TODO</summary>
+		public string Name   { get { return _name;   } } readonly string _name;
+		/// <summary>TODO</summary>
+		public double Factor { get { return _factor; } } readonly double _factor;
 
-        /// <summary>TODO</summary>
-        public double Length(double seconds) => seconds * _factor;
-    }
+		/// <summary>TODO</summary>
+		public double Length(double seconds) => seconds * _factor;
+	}
 
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
+    /// <remarks>
+    /// Tone number (or alternatively, Piano-Key number) is calculated as
+    /// base tome plus/minus enum Value.
+    /// </remarks>
 	public enum SharpFlat {
-    /// <summary>TODO</summary>
+	    /// <summary>TODO</summary>
 		FlatFlat	= -2,
-    /// <summary>TODO</summary>
+	    /// <summary>TODO</summary>
 		Flat		= -1,
-    /// <summary>TODO</summary>
+	    /// <summary>TODO</summary>
 		Natural		=  0,
-    /// <summary>TODO</summary>
+	    /// <summary>TODO</summary>
 		Sharp		= +1,
-    /// <summary>TODO</summary>
+	    /// <summary>TODO</summary>
 		SharpSharp	= +2		// "\uD834\uDD2A" or U+1D12A
 	}
 
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 	public enum OctaveShift {
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		Down	= -1,
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		Up		= +1
 	}
 
-    #pragma warning disable
-    public enum Mode { maj,  min,	lyd,	ion,	mix,	dor,	aeo,	phr,	loc }
+	#pragma warning disable
+	public enum Mode { maj,  min,	lyd,	ion,	mix,	dor,	aeo,	phr,	loc }
 
 	public enum NoteLetter { C, D, E, F, G, A, B, c, d, e, f, g, a, b }
-    #pragma warning restore
+	#pragma warning restore
 
-    #pragma warning disable
-    public enum PianoKey {           Bar = 89, Rest = 0, A_0, Bf_0, B_0,	//  1 ->  3
+	#pragma warning disable
+	public enum PianoKey {                     Rest = 0, A_0, Bf_0, B_0,	//  1 ->  3
 		C_1, Cs_1, D_1, Ef_1, E_1, F_1, Fs_1, G_1, Af_1, A_1, Bf_1, B_1,	//  4 -> 15
 		C_2, Cs_2, D_2, Ef_2, E_2, F_2, Fs_2, G_2, Af_2, A_2, Bf_2, B_2,	// 16 -> 27
 		C_3, Cs_3, D_3, Ef_3, E_3, F_3, Fs_3, G_3, Af_3, A_3, Bf_3, B_3,	// 28 -> 39
@@ -137,19 +142,20 @@ public enum PianoKey {           Bar = 89, Rest = 0, A_0, Bf_0, B_0,	//  1 ->  3
 		C_5, Cs_5, D_5, Ef_5, E_5, F_5, Fs_5, G_5, Af_5, A_5, Bf_5, B_5,	// 52 -> 63
 		C_6, Cs_6, D_6, Ef_6, E_6, F_6, Fs_6, G_6, Af_6, A_6, Bf_6, B_6,	// 64 -> 75
 		C_7, Cs_7, D_7, Ef_7, E_7, F_7, Fs_7, G_7, Af_7, A_7, Bf_7, B_7,	// 76 -> 87
-		C_8
-	}
-    #pragma warning restore
+		C_8,
+        Bar = 89
+    }
+	#pragma warning restore
 
-    /// <summary>TODO</summary>
-    public static class EnumExtensions {
+	/// <summary>TODO</summary>
+	public static class EnumExtensions {
 		#region SharpFlat extensions
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 		public static SharpFlat Parse(this SharpFlat sharpFlat, string s) {
 			return FromString(sharpFlat, s);
 		}
 
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 		public static SharpFlat FromString(this SharpFlat sharpFlat, string s) {
 			switch (s ?? string.Empty) {
 				case "-":
@@ -173,14 +179,14 @@ public static SharpFlat FromString(this SharpFlat sharpFlat, string s) {
 			}
 		}
 		static string[] symbols = {"♭♭", "♭", "♮", "♯", "♯♯"};
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 		public static string AsString(this SharpFlat sharpFlat) {
 			return symbols [(int)sharpFlat + 2];
 		}
 		#endregion SharpFlat extensions
 
 		#region OctaveShift extensions
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static OctaveShift FromString(this OctaveShift octaveShift, string value) {
 			switch (value.Trim(new char[] {'o','O'})) {
 				case "<":	return OctaveShift.Down;
@@ -189,37 +195,37 @@ public static OctaveShift FromString(this OctaveShift octaveShift, string value)
 									"input string must end in '<' or '>'.");
 			}
 		}
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static string AsString(this OctaveShift shift) { return shift.ToString(); }
 		#endregion OctaveShift extensions
 
 		#region NoteLettter extensions
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static NoteLetter Parse (this NoteLetter letter, string s) {
 			return (NoteLetter)System.Enum.Parse(typeof(NoteLetter),s);
 		}
-        /// <summary>
-        /// Returns the index for the base note according to:
-        /// <b>F</b>ather <b>C</b>harles <b>G</b>oes <b>D</b>own <b>A</b>nd <b>E</b>nds <B>B</B>attle.
-        /// </summary>
-        /// <param name="baseNote"></param>
-        /// <returns></returns>
-        public static Int16 FCGDAEB(this NoteLetter baseNote) {
-            return (Int16)"FCGDAEB".IndexOf(baseNote.ToString()[0]);	
+		/// <summary>
+		/// Returns the index for the base note according to:
+		/// <b>F</b>ather <b>C</b>harles <b>G</b>oes <b>D</b>own <b>A</b>nd <b>E</b>nds <B>B</B>attle.
+		/// </summary>
+		/// <param name="baseNote"></param>
+		/// <returns></returns>
+		public static Int16 FCGDAEB(this NoteLetter baseNote) {
+			return (Int16)"FCGDAEB".IndexOf(baseNote.ToString()[0]);	
 		}
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static int SemitonesFromC (this NoteLetter note) {
-            return (new int[] { 0, 2, 4, 5, 7, 9,11
-                              ,12,14,16,17,19,21,23}) [(int)note];
+			return (new int[] { 0, 2, 4, 5, 7, 9,11
+							  ,12,14,16,17,19,21,23}) [(int)note];
 		}
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static int NoteIndex (this NoteLetter note) {
 			return "CDEFGABcdefgab".IndexOf(note.ToString());
 		}
 		#endregion
 
 		#region Mode extensions
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 		public static string AsString(this Mode mode) {
 			switch (mode) {
 				case Mode.maj: return "major";
@@ -235,7 +241,7 @@ public static string AsString(this Mode mode) {
 					"Invalid enumeration value.");
 			}
 		}
-    /// <summary>TODO</summary>
+	/// <summary>TODO</summary>
 		public static NoteLetter BaseNote(this Mode mode) {
 			switch (mode) {
 				case Mode.min: 
@@ -254,11 +260,11 @@ public static NoteLetter BaseNote(this Mode mode) {
 		#endregion Mode extensions
 
 		#region PianoKey extensions
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static int Octave(this PianoKey @this) {
 			return ((int)@this + 8) / 12;
 		}
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static NoteLetter Letter(this PianoKey @this, int countSharps = 0) {
 			var noteNo	= ((new int[] {4,5,6,6,0,0,1,2,2,3,3,4}) [((int)@this) % 12]);
 							//  C   D   E F   G   A   B	// favour G# in sharp keys; A_ otherwise
@@ -266,12 +272,12 @@ public static NoteLetter Letter(this PianoKey @this, int countSharps = 0) {
 			if ((new int[] {0,4,0,0,7,0,5,0,0,0,0,6})[noteNo] >=-countSharps && countSharps<0) noteNo++;
 			return (NoteLetter)noteNo;
 		}
-        /// <summary>TODO</summary>
+		/// <summary>TODO</summary>
 		public static SharpFlat Accidental(this PianoKey key) {
 			var index = ((int)key) % 12;
 			return (SharpFlat)((new int[] {-1,0,-1,0,0,1,0,-1,0,0,1,0})[index]);
 		}
-		// Key  A_ A  B_ B  C  C# D  E_ E  F  F# G    A_  A  B_ B  C  C# D  E_ E  F  F# G
+		// Key    A_ A  B_ B  C  C# D  E_ E  F  F# G     A_  A  B_ B  C  C# D  E_ E  F  F# G
 		// F#	{ 4, 5, 5, 6, 6, 0, 1, 1, 2, 2, 3, 4}	{ 0,-1, 0,-1, 0, 0,-1, 0,-1, 0, 0,-1}	B
 		// C#	{ 4, 5, 5, 6, 0, 0, 1, 1, 2, 2, 3, 4}	{ 0,-1, 0, 0,-1, 0,-1, 0,-1, 0, 0,-1}	E
 		// B	{ 4, 5, 5, 6, 0, 0, 1, 1, 2, 3, 3, 4}	{ 0,-1, 0, 0,-1, 0,-1, 0, 0,-1, 0,-1}	A