diff --git a/Note.py b/Note.py
index 0433ed0..dd98c9d 100644
--- a/Note.py
+++ b/Note.py
@@ -1,4 +1,5 @@
 from enum import Enum
+from parser import ParseError
 
 class NotePitch(Enum):
     C = 1
@@ -16,12 +17,15 @@ class NotePitch(Enum):
     
     @staticmethod
     def toPitch(string):
-        map = { 'c': NotePitch.C, 'c#': NotePitch.CIS, 'db': NotePitch.CIS, 'd': NotePitch.D,
-               'd#': NotePitch.DIS, 'eb': NotePitch.DIS, 'e': NotePitch.E, 'fb': NotePitch.E, 'e#': NotePitch.F,
-               'f': NotePitch.F, 'f#': NotePitch.FIS, 'gb': NotePitch.FIS, 'g': NotePitch.G, 'g#': NotePitch.GIS,
-               'ab': NotePitch.GIS, 'a': NotePitch.A, 'a#': NotePitch.AIS, 'b': NotePitch.AIS, 'h': NotePitch.H
-               }
-        return map[string.lower()]
+        try:
+            map = { 'c': NotePitch.C, 'c#': NotePitch.CIS, 'db': NotePitch.CIS, 'd': NotePitch.D,
+                'd#': NotePitch.DIS, 'eb': NotePitch.DIS, 'e': NotePitch.E, 'fb': NotePitch.E, 'e#': NotePitch.F,
+                'f': NotePitch.F, 'f#': NotePitch.FIS, 'gb': NotePitch.FIS, 'g': NotePitch.G, 'g#': NotePitch.GIS,
+                'ab': NotePitch.GIS, 'a': NotePitch.A, 'a#': NotePitch.AIS, 'b': NotePitch.AIS, 'h': NotePitch.H
+                }
+            return map[string.lower()]
+        except KeyError as e:
+            raise ParseError(f"Note '{string}' does not exist")
 
 class Note:
     def __init__(self, note, octave, duration):        
diff --git a/note.py b/note.py
deleted file mode 100644
index fd080da..0000000
--- a/note.py
+++ /dev/null
@@ -1,36 +0,0 @@
-from enum import Enum
-
-class NotePitch(Enum):
-    C = 1
-    CIS = 2
-    D = 3
-    DIS = 4
-    E = 5
-    F = 6
-    FIS = 7
-    G = 8
-    GIS = 9
-    A = 10
-    AIS = 11
-    H = 12
-    
-    @staticmethod
-    def toPitch(string):
-        map = { 'c': NotePitch.C, 'c#': NotePitch.CIS, 'db': NotePitch.CIS, 'd': NotePitch.D,
-               'd#': NotePitch.DIS, 'eb': NotePitch.DIS, 'e': NotePitch.E, 'fb': NotePitch.E, 'e#': NotePitch.F,
-               'f': NotePitch.F, 'f#': NotePitch.FIS, 'gb': NotePitch.FIS, 'g': NotePitch.G, 'g#': NotePitch.GIS,
-               'ab': NotePitch.GIS, 'a': NotePitch.A, 'a#': NotePitch.AIS, 'b': NotePitch.AIS, 'h': NotePitch.H
-               }
-        return map[string]
-
-class Note:
-    def __init__(self, note, octave, duration):        
-        if type(note) == str:            
-            self.note = NotePitch.toPitch(note)
-        else:
-            self.note = note
-        self.octave = octave
-        self.duration = duration
-        
-    def __str__(self):
-        return f"{self.note}[{self.octave}, {self.duration}]"
diff --git a/tokenizer.py b/tokenizer.py
deleted file mode 100644
index 6037bc0..0000000
--- a/tokenizer.py
+++ /dev/null
@@ -1,199 +0,0 @@
-from enum import Enum
-import time
-import re
-import sys
-
-class TokenType(Enum):
-    OPEN_PAREN = 1
-    CLOSE_PAREN = 2
-    ASTERISK = 3
-    STRING = 4
-    IDENTIFIER = 5
-    COMMA = 6
-    INTEGER = 7
-    OPEN_BRACKET = 8
-    CLOSE_BRACKET = 9
-    ASSIGN = 10
-    COLON = 11
-    NOTE = 12
-    COMMENT = 13
-    PERCENT = 14
-    
-class TokenizerError(Exception):
-    pass
-    
-
-class Token:
-    def __init__(self, type, value, pos):
-        self.type = type
-        self.value = value    
-        self.pos = pos
-    def __str__(self):
-        return "Token(" + str(self.type) + ", '" + self.value + "', " + str(self.pos) + ")"
-    def __repr__(self):
-        return self.__str__()
-
-def tokenizeOpenParen(input, current, line):
-    if input[current] == '(':
-        return (1, Token(TokenType.OPEN_PAREN, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeCloseParen(input, current, line):
-    if input[current] == ')':
-        return (1, Token(TokenType.CLOSE_PAREN, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeAsterisk(input, current, line):
-    if input[current] == '*':
-        return (1, Token(TokenType.ASTERISK, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeString(input, current, line):
-    if input[current] == '"':
-        value = input[current]
-        char = ''
-        consumedChars = 1
-        while char != '"':
-            if char is None:
-                print("String not terminated")
-            char = input[current + consumedChars]
-            value += char
-            consumedChars += 1
-        return (consumedChars, Token(TokenType.STRING, value, (line, current)))
-    return (0, None)
-
-def tokenizeRegexPattern(type, pattern, input, current, line):    
-    consumedChars = 0
-    value = ''
-    
-    while current+consumedChars < len(input) and re.match(pattern, input[current+consumedChars]):
-        value += input[current+consumedChars]        
-        consumedChars += 1            
-    return (consumedChars, Token(type, value, (line, current)) if consumedChars > 0 else None)
-        
-def tokenizeWhitespaces(input, current, line):    
-    return tokenizeRegexPattern(None, r'\s', input, current, line)
-
-def tokenizeIdentifier(input, current, line):
-    return tokenizeRegexPattern(TokenType.IDENTIFIER, r'\w', input, current, line)
-
-def tokenizeComma(input, current, line):
-    if input[current] == ',':
-        return (1, Token(TokenType.COMMA, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeInteger(input, current, line):    
-    return tokenizeRegexPattern(TokenType.INTEGER, r'\d', input, current, line)
-
-def tokenizeOpenBracket(input, current, line):
-    if input[current] == '{':
-        return (1, Token(TokenType.OPEN_BRACKET, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeCloseBracket(input, current, line):
-    if input[current] == '}':
-        return (1, Token(TokenType.CLOSE_BRACKET, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeAssign(input, current, line):
-    if input[current] == '=':
-        return (1, Token(TokenType.ASSIGN, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeColon(input, current, line):
-    if input[current] == ':':
-        return (1, Token(TokenType.COLON, input[current], (line, current)))
-    return (0, None)
-
-def tokenizeComment(input, current, line):
-    if input[current] == '#':
-        consumedChars = 0
-        value = ''
-        while current+consumedChars < len(input):
-            value += input[current+consumedChars]
-            consumedChars += 1            
-            pass
-        return (consumedChars, Token(TokenType.COMMENT, value, (line, current)))
-    return (0, None)
-
-def tokenizeNote(input, current, line):
-    consumedChars = 0
-    value = ''
-    if input[current] == '@':
-        consumedChars += 1
-        value += input[current]
-        if input[current+consumedChars] in ('C', 'c', 'D', 'd', 'E', 'e', 'F', 'f', 'G', 'g', 'A', 'a', 'H', 'h', 'B', 'b'):
-            value += input[current+consumedChars]
-            consumedChars += 1
-            
-            if current+consumedChars < len(input) and input[current+consumedChars] in ('b', '#'):                        
-                value += input[current+consumedChars]
-                consumedChars += 1
-                
-            if current+consumedChars < len(input) and re.match(r'\d', input[current+consumedChars]):            
-                value += input[current+consumedChars]
-                consumedChars += 1
-                
-            if current+consumedChars < len(input) and input[current+consumedChars] == '.':            
-                value += input[current+consumedChars]
-                consumedChars += 1
-                while current+consumedChars < len(input) and re.match(r'\d', input[current+consumedChars]):
-                    value += input[current+consumedChars]        
-                    consumedChars += 1  
-            return (consumedChars, Token(TokenType.NOTE, value, (line, current)))
-    return (0, None)
-
-def tokenizePercent(input, current, line):
-    if input[current] == '%':
-        return (1, Token(TokenType.PERCENT, input[current], (line, current)))
-    return (0, None)
-
-tokenizers = (
-    tokenizeOpenParen, 
-    tokenizeCloseParen, 
-    tokenizeAsterisk, 
-    tokenizeString, 
-    tokenizeInteger,
-    tokenizeNote,
-    tokenizeIdentifier, 
-    tokenizeComma,
-    tokenizeOpenBracket,
-    tokenizeCloseBracket,
-    tokenizeAssign,
-    tokenizeColon,
-    tokenizePercent,
-    tokenizeComment,
-    tokenizeWhitespaces
-)
-
-def tokenize(lines):    
-    tokens = []         
-    for lineNumber, line in enumerate(lines):    
-        current = 0
-        while current < len(line):
-            tokenized = False
-            for tokenizer in tokenizers:
-                consumedChars, value = tokenizer(line, current, lineNumber)
-                if consumedChars > 0:
-                    tokens.append(value)
-                    current += consumedChars
-                    tokenized = True
-                    break            
-            
-            if not tokenized:
-                raise TokenizerError(f"Line {lineNumber+1}, col {current+1}: unknown symbol '{line[current]}'")
-            
-    return [token for token in tokens if token.type is not None]
-
-if __name__ == "__main__":   
-    try:
-        with open(sys.argv[1], 'r') as source:
-            lines = [line.rstrip('\n') for line in source.readlines()]
-            
-            tokens = tokenize(lines)    
-        
-        for token in tokens:
-            print(token)        
-    except TokenizerError as e:
-        print(str(e))
-