'Updates the start time, removing any notes that started before it.'

@start_time.setter
@concurrency.serialized
def start_time(self, value):

    self._start_time = value
    i = 0
    for note in self._captured_sequence.notes:
        if (note.start_time >= self._start_time):
            break
        i += 1
    del self._captured_sequence.notes[:i]
