In addition to music therapy, a kind of color theraphy was also used, since it was said that it was important to find the color of the biting spider. For this purpose, colored ribbons and other pieces of textile materials were put on the floor around the dancer. She had to find the right color and dance looking at it.
Sometime the patient had to find the place where she was bitten:then she would exit her home and continuing to dance with the musicians, go in the field where the illness had started. The patient would eventually proclaim herself "cured" for the remainder of the summer, only to relapse in subsequent summers. Apparently the musical cure wouldn't expel all the venom from the body. A small part of the poison would reamain to be reactivated next year by the heat of summer.
All this was told to me from relatives.The tarantism has continued in other places in southern Apulia also after World War II, and exists a detailed study about it written by Ernesto De Martino : La terra del rimorso (Il Saggiatore). Published also in english with the title The land of remorse
We have also a short movie by Gianfranco Mingozzi La taranta done in 1961 which shows part of the ritual and the meeting of the tarantate during the Saint Peter and Paul festival day in Galatina. The tarantate would travel from nearby villages to Saint Paul chapel to obtain a cure from the illness.
By now, it is well known that it is a form of mass hysteria similar to the "Dancing Mania" in Middle Age. Lycosa tarantula has a painful byte but without any consequence. Another smaller spider present in our fields, Latrodectus tarantula can instead produce psychoactive effects that in severe cases can be similar to tarantism symptoms.But this doesn't explain the presence of tarantism attacks, since the same spider was present elsewhere (and is present right now in Apulia and other parts of Italy) without any consequence.
Other information about tarantism:
Rethinking Dancing Mania Skeptical Inquirer , July 2000