Issue with writing chords to midi file

Hi,

I have a hard time writing chords in a MIDI file using MIDO, the MIDI library for Python.

I have a list of 100 chords with notes stored in the list. So each chord in the code below is [60, 63, 67] as in Cmin. The timing of each in seconds is stored in the chordTimes list.

I iterate in the list,

for i in range(1, len(chords)): 

    chordNotes = chordMidiNotes(chords[i], extraBass= False)[0]

    chordSymbol = chordMidiNotes(chords[i], extraBass= False)[1]

    for note_value in chordNotes: # result has chord notes

        track.append(Message('note_on', note=note_value, velocity=100, time=0))

    for note_value in chordNotes: # result has chord notes

        track.append(Message('note_off', note=note_value, velocity=127, time=time_in_ticks(chordTimes[i], mo)))

mo.save("songWithChords.mid")

But then when I open the files, the chords start at the same time, however, the top note ends just before last chords, the one below ends before that, the one before the later stops again several beats before it, .... as you see in the image. I am using type 1 midi file.



Any help would be appreciated.