def bpmToMs(bpm):
    """
        Method:
            Convert BPM to ms, where ms is the time in milliseconds between 2 beats.
        Argument:
            bpm (int or float) : the bpm to convert.
        Return:
            (int or float) : Time between 2 beats in ms.
    """
    if bpm <= 0:
        return 0
    else:
        return 60000/bpm