def read_lab_chords(filename):
chords = []
with open(filename) as f:
chord_lines = f.readlines()
chords = []
for line in chord_lines:
line = line.strip()
if not line:
continue
start, end, chord = line.split(' ')
start = float(start)
end = float(end)
chord = Chord.from_string(chord)
chords.append(TimedData(start, end, chord.get_number()))
return chords