In May 2013, Disembraining invited Mattin to Australia to conceive a series of works addressing the question What is not music? The question refers respectfully to the long-running Australian experimental festival What is Music? reframing it as negation in order to investigate -What sounds remain impossible to assimilate? What isn't music ? Mattin responded by creating the 5th edition of his songbook series: an ongoing work that uses 'improvisation as a way or exposing structural clichés in pop-rock music' and 'song structures to demystify the so-called spontaneity and freedom of improvisation'. Songbook 5 was created according to a strict set of conditions generated through an obsessively literal reiteration of the number 5. Yet it is clearly a rock' record in sound and feeling. As such it may be the most structurally determined rock album ever. An album that holds a mirror to rock's freedom, celebrating its own mediation.Songbook 5 features contributions from Joel Stern and Alex Cuffe (of Sky Needle), Andrew McLellan (of Cured Pink) and the legendary NZ guitarist Dean Roberts (Thela, White Winged Moth, Autistic Daughters). 7-8 May 2013, Melbourne, Australia.1: 5 musicians record 5 improvised songs of 5 minutes each addressing 5 concepts described in 5x5 word titles What Isn't Music After Cage? - Aware Of Its Own Mediation - Stuck In Our Own Trap - Alienation As An Enabling Condition - The Act Acting On Itself.2: Mattin performs a 25 minute concert with 5x5 minute sections structured by 5 instructions based on the song titles given to 5 members of the audience.3: Mattin records vocals for the 5 songs in the form of a singing lecture at the Victorian College of the Arts. The audience only hears Mattin's voice (he listens to the backing tracks on headphones).4: Recordings of parts 1, 2 and 3 are superimposed to create a 25 minute album consisting of 5x5 minute songs.5: Record released in an edition of 555 copies.