According to my research, idiolalla is a psychiatric condition in which those afflicted are compelled to make up their own private language. It’s kind of like a fundamentalist-free version of speaking in tongues, and chances are that if we encountered an idiolallite on the street, we’d scurry away, unnerved by their unfathomable barrage of words. Strange, then, that seeing two idiolalla victims on-stage, backed only by a drummer, should prove so fascinating.

Of course, singers Christine Duncan and DB Boyko don’t really suffer from the syndrome; they’ve just named their new group after it. Idiolalla, in which the two are joined by Duncan’s percussionist partner, Jean Martin, is an exploration of improvisational mouth music, and a chance for three serious musicians to have way too much fun.

That much was obvious from their VOX-festival set’s closing number, which began with Martin laying down an idiot-simple drum beat, like a kindergarten version of rock ‘n’ roll. The two singers then introduced a set of awkward and naive lyrics about rich people and poor people, skinny people and fat people: it was obvious the song was a cover, but of what? At last it dawned on me: this was Philosophy of the World, the title track from what some critics believe is the worst album ever — and thus pure genius in its own special way.

The chorus of “Philosophy…” is simple: “You can never please everybody in this world”. But by ending its debut show with a slice of the Shaggs — no doubt a first for any new-music festival, anywhere in the world — Idiolalla pleased at least as many in the musically literate crowd as it puzzled. In fact, the whole set was a blast.

Duncan and Boyko can sing anything, although the former is known for her jazz and gospel stylings while the latter has trained intensively in Java and Bali. Together, they seem bent on pushing each other ever-further into wordless glossolalia and gibberish, but because their approach is one of complicity rather than confrontation, those out-there warblings smack of effervescent joy. Martin adds colour and punctuation. Although it’s easy for music like this to slip over into self-indulgence, Idiolalla’s performance was too smart, nuanced. These three are on to something, and we wait with interest to see where they go next.