Released in November 2013, the multi-format set of recordings of Taylor Ho Bynum’s innovative composition for improvising sextet, Navigation, both culminates and continues his fascination with the interfaces between the extemporaneous and the written, the scripted and the performative. Separate LP and compact disc versions of the work are paired with different fragments of text from poet Nathaniel Mackey’s experimental epistolary novel Bass Cathedral, a book that Ho Bynum has recently said, for him, is probably the best writing about music he has encountered. Earlier compositions by Bynum, such as his suite Madeleine Dreams, have not only used prose fiction as libretto, but more tellingly have striven to address sonically and structurally the complex and often fraught relationships between the musical and the diegetic, between sound and sense. Navigationtakes up Mackey’s own address to this interface, sounding what Mackey understands as creative discrepancy, an expressive troubling of formal and cultural boundaries. Name-checking both Sun Ra and Louis Armstrong, Mackey has noted what he calls a “play of parallel estrangements” in improvised music and in poetry, arguing that music “is prod and precedent for a recognition that the linguistic realm is also the realm of the orphan,” that is, of the limits of sense, a liminal zone of both orchestration and letting go. Ho Bynum’s recordings pick up not only on Mackey’s thorough enmeshment in jazz history, but also on his intention to pursue the expressive potential of language and of music at their textural boundaries, at moments of troubling contact between divergent worldviews, or between dissimilar social and cultural genetics. Composing using what Mackey calls m’apping – a portmanteau splice of mapping and mishap, pursuing what Mackey calls the “demiurgic rumble” of discrepancy, improvising across the gaps between careful craft and unruly noise – Ho Bynum conjures a hybrid and collaborative music that blends the complex Afrological heritages of jazz performance style (audible in Navigation’s network of gestures to Charles Mingus and Duke Ellington, to name only two key forebears) with graphic scoring techniques derived from Sylvano Bussotti or Wadada Leo Smith, among others. If improvised music, for Mackey, represents – and represents precisely – what defies descriptive capture in language, what eludes ekphrasis, then the music of Taylor Ho Bynum’s sextet aspires to invert that representational effort, to take up the discrepant aesthetic tactics of Mackey’s writing and to assess how the written (as graphē, as graphic score) can approach and test the expressive limits of making music happen. Taylor Ho Bynum’s compositions for improvisers offer exemplary instances of how to negotiate creatively the boundaries between text and sounding, and suggest a means of addressing, too, the graphic work of other composer-improvisers, including the work of Nicole Mitchell, Anthony Braxton and Barry Guy