def note_number_to_hz(note_number):
    # MIDI note numbers are defined as the number of semitones relative to C0
    # in a 440 Hz tuning
    return 440.0*(2.0**((note_number - 69)/12.0))
Test the |localtime, |utc, and |timezone filters on bad inputs.
dataset/ETHPy150Open craffel/pretty-midi/pretty_midi/utilities.py/note_number_to_hz--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/tests/modeltests/timezones/tests.py/TemplateTests.test_localtime_filters_do_not_raise_exceptions