This chapter argues that the history of visual music across its various trajectories can be viewed as a quest for an audiovisual language, based on identifying absolutes in the audiovisual itself. Rather than a vocabulary based on the properties of sound and image, it is proposed that visual music is a form of glossolalic discourse between practitioner, sound and image (the work) and the audience. This discourse suggests the coherence of a language, but as with speaking in tongues is to a degree always indecipherable, underpinned as it is by a fluid syntax, combining elements of audiovisual adhesion, counterpointing, synthesis and dissonance. It is this element of indecipherability, of being always somewhat beyond comprehension that affords visual music the ‘gift of sound and vision’. This aspect facilitates synaesthesia, and the potential for visual music to be experienced as immersive, or even on occasion induce hypnogogic trance. Such aspects are inherent in the glossolalic nature of visual music, but can be either encouraged, or brought into reflexive relief by the composer.