Added generate.py

This code is used to generate new music (in MIDI format) using the trained model (model.hdf5).

Author: matakshay

generate.py

@@ -0,0 +1,92 @@
+# Generate music using the model trained earlier
+
+from keras.models import load_model
+import numpy as np
+import pickle
+from music21 import converter, instrument, note, chord, stream
+
+notes = []
+
+with open ("notes", "rb") as file:
+    notes = pickle.load(file)
+
+pitch_names = sorted(set(notes))
+
+model = load_model("model.hdf5")
+
+# Create a mapping from int to element
+int_to_element = dict ((num, element) for num, element in enumerate (pitch_names))
+element_to_int = dict ((element, num) for num, element in int_to_element.items())
+
+sequence_length = 100
+
+test_input = []
+
+for i in range (len(notes) - sequence_length):
+    seq_inp = notes[i:i+sequence_length]
+    test_input.append([element_to_int[ch] for ch in seq_inp])
+
+vocab_len = 359
+
+# Randomly select a sequence of notes from test_input
+start = np.random.randint(len(test_input)-1)
+
+
+# Feed this to model and get prediction
+pattern = test_input[start]
+final_prediction = []
+print("Running the model...")
+
+for note_index in range(200):
+    pred_inp = np.reshape(pattern, (1, len(pattern), 1))
+    inp = pred_inp/float(vocab_len)
+
+    prediction = model.predict(inp, verbose=0)
+    idx = np.argmax(prediction)
+    result = int_to_element[idx]
+
+    # Append this predicted note output to final_prediction
+    final_prediction.append(result)
+
+    # Next input to model should also have same size
+    # So use this same input, but drop the first note and append the predicted note
+    pattern = pattern[1:]
+    pattern.append(idx)
+
+print("Music generated!")
+# Create MIDI files
+print("Creating MIDI file...")
+
+offset = 0  #Time
+final_notes = []
+
+for pattern in final_prediction:
+    #If pattern is a chord
+    if ('+' in pattern ) or pattern.isdigit():
+        notes_in_chord = pattern.split('+')
+        temp_notes = []
+
+        for curr_note in notes_in_chord:
+            # For each note in the chord, create a new Note object
+            new_note = note.Note(int(curr_note))
+            new_note.storedInstrument = instrument.Piano()
+            temp_notes.append(new_note)
+
+        new_chord = chord.Chord(temp_notes)
+        new_chord.offset = offset
+        final_notes.append(new_chord)
+
+    #If pattern is a note
+    else:
+        curr_note = note.Note(pattern)
+        curr_note.offset = offset
+        curr_note.storedInstrument = instrument.Piano()
+        final_notes.append(curr_note)
+
+    offset += 0.5
+
+
+# Create a stream object from the generated notes
+MIDI_stream = stream.Stream(final_notes)
+MIDI_stream.write('midi', fp = 'output.mid')
+print("Music saved as \"output.mid\" in current directory")