Whereas ethnomusicology uses musical tools to analyse sound, the itinerant musicians (Kerala) invited me to consider music as made of visual elements, using kalams (ritual drawings) as a reference. The making of several metres large drawings on the floor with the help of different colours and powders is an integral part of the ritual activity of the musicians. The kalam is not only used as a privileged means to call the deities or make them appear, it is also a common way used by the musicians themselves to talk about musical form (rupam), melodic structures, sound variations and combinations. A detailed study of the musical and graphic repertoires shows complex interplays between visual and sound which must be thought here as two interdependant variables.