Canadian poet and artist Brenda Clews does it all here: drawing, filming, editing, even constructing the music. “The world is a green furor of creativity – the green fire of life,” she writes in the description at YouTube, where she provides a detailed description of her process, including this note about the music:
I created the music in a cool program, a ‘P22 Music Text Composition Generator (A free online music utility)': http://www.p22.com/musicfont In this program, each letter has a sound. When you put text in, you can choose what BMP and instrument you’d like, and the program generates a midi file, with the sheet music. I layered my track in GarageBand 6.0.2 using different instruments, splicing and re-arranging. [...]
From start to finish took about 12 hours, there were many layers, of image, text, and sound, each with filters, and I had to render a few times, which took hours, to see if what I had produced worked.