diff --git a/include/hiddenmarkovmodel.h b/include/hiddenmarkovmodel.h
index 13341aa..030f475 100644
--- a/include/hiddenmarkovmodel.h
+++ b/include/hiddenmarkovmodel.h
@@ -71,20 +71,21 @@ class HiddenMarkovModel {
         std::map<std::string, double> > m_emissionProbabilities;
 
  public:
+    typedef std::vector<Key> KeySequence;
     HiddenMarkovModel(
         std::vector<PitchClass> observations,
         Key::KeyVector states,
         std::map<Key, double> initialProbabilities,
         std::map<Key, std::map<Key, double> > transitionProbabilities,
         std::map<Key, std::map<PitchClass, double> > emissionProbabilities);
-    // HiddenMarkovModel(
-    //     std::vector<Key> observations,
-    //     Key::KeyVector states,
-    //     std::map<Key, double> initialProbabilities,
-    //     std::map<Key, std::map<Key, double> > transitionProbabilities,
-    //     std::map<Key, std::map<Key, double> > emissionProbabilities);
+    HiddenMarkovModel(
+        std::vector<Key> observations,
+        Key::KeyVector states,
+        std::map<Key, double> initialProbabilities,
+        std::map<Key, std::map<Key, double> > transitionProbabilities,
+        std::map<Key, std::map<Key, double> > emissionProbabilities);
     void printOutput();
-    void runViterbi();
+    KeySequence runViterbi();
 };
 
 
diff --git a/src/hiddenmarkovmodel.cc b/src/hiddenmarkovmodel.cc
index 558f615..174f991 100644
--- a/src/hiddenmarkovmodel.cc
+++ b/src/hiddenmarkovmodel.cc
@@ -82,55 +82,55 @@ HiddenMarkovModel::HiddenMarkovModel(
   }
 }
 
-// HiddenMarkovModel::HiddenMarkovModel(
-//   std::vector<Key> observations,
-//   Key::KeyVector states,
-//   std::map<Key, double> initialProbabilities,
-//   std::map<Key, std::map<Key, double> > transitionProbabilities,
-//   std::map<Key, std::map<Key, double> > emissionProbabilities) {
-//   // Observations
-//   for (std::vector<Key>::const_iterator itObs = observations.begin();
-//       itObs != observations.end(); itObs++) {
-//     m_observations.push_back(itObs->getInt());
-//   }
-//   // States
-//   for (std::vector<Key>::const_iterator itState = states.begin();
-//       itState != states.end(); itState++) {
-//     m_states.push_back(itState->getString());
-//   }
-//   // Initial probabilities
-//   for (std::map<Key, double>::const_iterator itInitial =
-//       initialProbabilities.begin(); itInitial != initialProbabilities.end();
-//       itInitial++) {
-//     std::string key = (itInitial->first).getString();
-//     m_initialProbabilities[key] =
-//         itInitial->second;
-//   }
-//   // Transition probabilities
-//   for (std::map<Key, std::map<Key,
-//       double> >::const_iterator itTransition = transitionProbabilities.begin();
-//       itTransition != transitionProbabilities.end(); itTransition++) {
-//     std::string fromKey = (itTransition->first).getString();
-//     std::map<Key, double> toKeyMap = itTransition->second;
-//     for (std::map<Key, double>::const_iterator itToKey = toKeyMap.begin();
-//         itToKey != toKeyMap.end(); itToKey++ ) {
-//       std::string toKey = (itToKey->first).getString();
-//       m_transitionProbabilities[fromKey][toKey] = itToKey->second;
-//     }
-//   }
-//   // Emission probabilities
-//   for (std::map<Key, std::map<PitchClass,
-//       double> >::const_iterator itEmission = emissionProbabilities.begin();
-//       itEmission != emissionProbabilities.end(); itEmission++) {
-//     std::string fromKey = (itEmission->first).getString();
-//     std::map<PitchClass, double> emitPcMap = itEmission->second;
-//     for (std::map<PitchClass, double>::const_iterator itEmitPc =
-//         emitPcMap.begin(); itEmitPc != emitPcMap.end(); itEmitPc++) {
-//       int emitPc = (itEmitPc->first).getInt();
-//       m_emissionProbabilities[fromKey][emitPc] = itEmitPc->second;
-//     }
-//   }
-// }
+HiddenMarkovModel::HiddenMarkovModel(
+  std::vector<Key> observations,
+  Key::KeyVector states,
+  std::map<Key, double> initialProbabilities,
+  std::map<Key, std::map<Key, double> > transitionProbabilities,
+  std::map<Key, std::map<Key, double> > emissionProbabilities) {
+  // Observations
+  for (std::vector<Key>::const_iterator itObs = observations.begin();
+      itObs != observations.end(); itObs++) {
+    m_observations.push_back(itObs->getString());
+  }
+  // States
+  for (std::vector<Key>::const_iterator itState = states.begin();
+      itState != states.end(); itState++) {
+    m_states.push_back(itState->getString());
+  }
+  // Initial probabilities
+  for (std::map<Key, double>::const_iterator itInitial =
+      initialProbabilities.begin(); itInitial != initialProbabilities.end();
+      itInitial++) {
+    std::string key = (itInitial->first).getString();
+    m_initialProbabilities[key] =
+        itInitial->second;
+  }
+  // Transition probabilities
+  for (std::map<Key, std::map<Key,
+      double> >::const_iterator itTransition = transitionProbabilities.begin();
+      itTransition != transitionProbabilities.end(); itTransition++) {
+    std::string fromKey = (itTransition->first).getString();
+    std::map<Key, double> toKeyMap = itTransition->second;
+    for (std::map<Key, double>::const_iterator itToKey = toKeyMap.begin();
+        itToKey != toKeyMap.end(); itToKey++ ) {
+      std::string toKey = (itToKey->first).getString();
+      m_transitionProbabilities[fromKey][toKey] = itToKey->second;
+    }
+  }
+  // Emission probabilities
+  for (std::map<Key, std::map<Key,
+      double> >::const_iterator itEmission = emissionProbabilities.begin();
+      itEmission != emissionProbabilities.end(); itEmission++) {
+    std::string fromKey = (itEmission->first).getString();
+    std::map<Key, double> emitKeyMap = itEmission->second;
+    for (std::map<Key, double>::const_iterator itEmitKey =
+        emitKeyMap.begin(); itEmitKey != emitKeyMap.end(); itEmitKey++) {
+      std::string emitKey = (itEmitKey->first).getString();
+      m_emissionProbabilities[fromKey][emitKey] = itEmitKey->second;
+    }
+  }
+}
 
 void HiddenMarkovModel::printOutput() {
   // print states
@@ -178,7 +178,8 @@ void HiddenMarkovModel::printOutput() {
   }
 }
 
-void HiddenMarkovModel::runViterbi() {
+HiddenMarkovModel::KeySequence HiddenMarkovModel::runViterbi() {
+  KeySequence keySequence;
   std::map<std::string, Tracking> T;
 
   for (std::vector<std::string>::iterator state=m_states.begin();
@@ -232,6 +233,14 @@ void HiddenMarkovModel::runViterbi() {
     }
   }
 
+  final_tracker.v_path.pop_back();
+
+  for (std::vector<std::string>::const_iterator itNode =
+    final_tracker.v_path.begin(); itNode != final_tracker.v_path.end();
+    itNode++) {
+    keySequence.push_back(Key(*itNode));
+  }
+
   std::cout << "Total probability of the observation sequence: "
        << final_tracker.prob << std::endl;
   std::cout << "Probability of the Viterbi path: "
@@ -241,6 +250,8 @@ void HiddenMarkovModel::runViterbi() {
   state != final_tracker.v_path.end(); state++) {
     std::cout << "VState: " << *state << std::endl;
   }
+
+  return keySequence;
 }
 
 }  // namespace justkeydding
diff --git a/test/test_hiddenmarkovmodel.cc b/test/test_hiddenmarkovmodel.cc
index 3419414..210d940 100644
--- a/test/test_hiddenmarkovmodel.cc
+++ b/test/test_hiddenmarkovmodel.cc
@@ -44,35 +44,14 @@ using justkeydding::HiddenMarkovModel;
 
 
 int main(int argc, char *argv[]) {
+    ////////////////////////////
+    // First Hidden Markov Model
+    ////////////////////////////
     // Observation symbols section
     std::vector<PitchClass> pitchClassSequence;
     pitchClassSequence.push_back(PitchClass("C"));
-    pitchClassSequence.push_back(PitchClass("D"));
     pitchClassSequence.push_back(PitchClass("E"));
-    pitchClassSequence.push_back(PitchClass("F"));
     pitchClassSequence.push_back(PitchClass("G"));
-    pitchClassSequence.push_back(PitchClass("A"));
-    pitchClassSequence.push_back(PitchClass("B"));
-    pitchClassSequence.push_back(PitchClass("A"));
-    pitchClassSequence.push_back(PitchClass("G"));
-    pitchClassSequence.push_back(PitchClass("F#"));
-    pitchClassSequence.push_back(PitchClass("E"));
-    pitchClassSequence.push_back(PitchClass("D"));
-    pitchClassSequence.push_back(PitchClass("C#"));
-    pitchClassSequence.push_back(PitchClass("D"));
-    pitchClassSequence.push_back(PitchClass("E"));
-    pitchClassSequence.push_back(PitchClass("F#"));
-    pitchClassSequence.push_back(PitchClass("G"));
-    pitchClassSequence.push_back(PitchClass("A"));
-    pitchClassSequence.push_back(PitchClass("B"));
-    pitchClassSequence.push_back(PitchClass("C"));
-    pitchClassSequence.push_back(PitchClass("B"));
-    pitchClassSequence.push_back(PitchClass("A"));
-    pitchClassSequence.push_back(PitchClass("G"));
-    pitchClassSequence.push_back(PitchClass("F"));
-    pitchClassSequence.push_back(PitchClass("E"));
-    pitchClassSequence.push_back(PitchClass("D"));
-    pitchClassSequence.push_back(PitchClass("C"));
     // States section
     Key::KeyVector keyVector =
         Key::getAllKeysVector();
@@ -90,12 +69,24 @@ int main(int argc, char *argv[]) {
     // Emission probabilities
     KeyProfile::KeyProfileMap emissionProbabilities =
         KeyProfile("temperley", "sapp").getKeyProfileMap();
+    HiddenMarkovModel::KeySequence keySequence;
     HiddenMarkovModel hmm(
         pitchClassSequence,
         keyVector,
         initialProbabilities,
         transitionProbabilities,
         emissionProbabilities);
-    // hmm.printOutput();
-    hmm.runViterbi();
+    keySequence = hmm.runViterbi();
+    /////////////////////////////
+    // Second Hidden Markov Model
+    /////////////////////////////
+    KeyTransition::KeyTransitionMap zeroTransiionProbabilities =
+        KeyTransition("zero").getKeyTransitionMap();
+    HiddenMarkovModel hmm2(
+        keySequence,
+        keyVector,
+        initialProbabilities,
+        zeroTransiionProbabilities,
+        transitionProbabilities);
+    HiddenMarkovModel::KeySequence mainKeySequence = hmm2.runViterbi();
 }