ValueError: need more than 0 values to unpack

[urumo]

Traceback (most recent call last):
File "generator.py", line 193, in
main(sys.argv)
File "generator.py", line 188, in main
generate(data_fn, out_fn, N_epochs)
File "generator.py", line 107, in generate
chords, abstract_grammars = get_musical_data(data_fn)
File "/media/aram/Mordigan/How-to-Generate-Music-Demo-master/preprocess.py", line 130, in get_musical_data
measures, chords = __parse_midi(data_fn)
File "/media/aram/Mordigan/How-to-Generate-Music-Demo-master/preprocess.py", line 25, in __parse_midi
melody1, melody2 = melody_stream.getElementsByClass(stream.Voice)
ValueError: need more than 0 values to unpack

and what do I do now?

[Echo-Ji]

ADVISE:
You can just use "try-except" to catch the exception and debug it.
code like:

    try:
        melody1, melody2 = melody_stream.getElementsByClass(stream.Voice)
    except:
        print line