HEY I’VE HEARD ABOUT THIS PROJECT! This is a singing synth engine being developed by the folks over at Voctro Labs and they have a bit of experience making spanish Vocaloid voicebanks. In fact the female spanish voice on that page is the same one used in their Maika bank.
By the way you can read the more technical details about it over on it’s research paper https://arxiv.org/abs/1704.03809
