如何用Python编写MIDI文件？

I am writing a script to convert a picture into MIDI notes based on the RGBA values of the individual pixels. However, I cannot seem to get the last step working, which is to actually output the notes to a file. I have tried using the MIDIUtil library, however it's documentation is not the greatest and I can't seem to figure it out. If anyone could tell me how to sequence the notes (so that they don't all begin at the beginning) it would be greatly appreciated.I am writing a script to convert a picture into