Melancholy, to Ficino, is a state in which the mind, the realm of deep, abstract thinking, is cut off from the supply of the spirit. His concept of spirit corresponds to a kind of universal life-energy (libido, in Jungian terms). Individually, as the spirit of man, it appears as projected into the blood of the human body, collectively, as spirit of the world, into the spheres of the planets.
The spirit of man corresponds to the spirit of the world and can receive from it a great deal through the rays of the planets. To attract the ‘spiritual’ influence of a particular planet you may use animals, plants, food, scents, talismans. But music is what is recommended most strongly.
Ficino's intention is to temper the melancholic influence of Saturn. Consequently, his astrological songs are addressed to the compensating benign planets, the Sun, Jupiter and Venus. In modern terms it is an attempt, consciously, by active imagination, to re-establish the emotional relatedness with the archetypal realms of the planets from which Saturn has cut us off.
Ficino's ideas are related to Jung's rehabilitation of the feeling-function