For Jane Hatter, community conjures people united by a common place or cause, shared skills, goals, values, a language of codes and symbols, and tools understood by an inner circle. Composing denotes knowing, crafting, and communicating. Acts and artifacts defined and identified professional musical communities and, half a millennium later, they still express identity and belonging. The book's subtitle, Self-Reference, Pedagogy, and Practice, identifies avenues of musical communication. The narrative begins with Machaut, whose self-awareness introduced many of the signs and techniques invoked by later composers: anagrams signaling identity, close bonds between music and text, and the intentional creation of a material legacy—for Machaut, manuscripts made under his supervision. Later composers followed Machaut's model of self-identification: Du Fay, Agricola, Josquin, and others signed their works through musical and textual puzzles.

The same material and artistic impulse manifests again in the Chantilly Codex, which contains six “musicians’ motets”—works listing names of musicians, linked and preserved for posterity. Composers in subsequent generations continued the practice, memorializing dozens of colleagues, especially composers, who shared each other's company in choirs, chapels, and courts in their lifetimes, and remain bound together in memory. Musicians inserted themselves and their colleagues into their motets by displaying the tools at the foundation of their practice, especially the solfege syllables attributed to Guido and the associated notated hexachord—essentially, the universe of aural and visual music. Hatter equates musicians’ motets and painters’ paintings, observing that composers and painters similarly invited viewers to see them practicing their craft in self-portraits where they display their tools and themselves at work. Hatter compares Rogier van der Weyden's Saint Luke Drawing the Virgin with Du Fay's Ave Regina Celorum III. Van der Weyden portrays the evangelist as himself, reminding viewers that Saint Luke was a painter like himself and his peers, who also venerate the Virgin. In his motet, Du Fay names first himself and then his community in a prayer for all of their souls. In such motets, Hatter notes that “both devotional images and the prayer texts of motets regularly crossed the threshold between the private spaces of Books of Hours and the semipublic and public spaces of votive altars” (23). Music's immateriality makes it difficult to present as evidence; the analogy of its visual counterpart grounds music's tools and practices as professional equivalents.

Case studies draw connections between music and cultural norms, encompassing, for example, professional promotion through guild membership, liturgical observance (universal or specific to a place and time), and concerns for the welfare of souls of musicians, patrons, and audiences. Comparison and analysis yield new conclusions, even from well-known works. Du Fay's Marian motet Fulgens Iubar comprises intricate intersections that reveal the composer's artistry and skill. Within the formal structure of this isorhythmic motet, liturgical and ritual texts point to a related object (a silver reliquary bearing the three final words of the cantus firmus), form an acrostic message to a Cambrai choirmaster, suggest a performance scenario, and generate intertextual synergy between the poem's two juxtaposed refrains. Mary's plea “My son, forgive sins!” amplifies the work's meaning as it sounds simultaneously with the singers’ petition, “May [we] be raised aloft in the dwellings of the saints.”

A motet by Josquin provides the ultimate example for Hatter's arguments. Like Du Fay's motet, Illibata Dei Virgo Nutrix praises the Virgin while pleading for her intercession on behalf of musicians. Josquin combines a panoply of techniques to communicate professionalism and relationships—an acrostic of his name, hexachords, and a cantus firmus evoking the name Maria through the solfege syllables, la mi la—each technique situated for maximum effect. Hatter observes, “As creators of enduring written musical prayers, composers were master users of the tools of the musical trade, arranging them for patrons, for their own remembrances, and for the benefit of their whole community” (216). Deciphering music's preserved messages raises a curtain on a time that still holds mysteries, revealing communities that shared spiritual and social values and beliefs, modes of communication and living, and a profession inherently capable of the most subtle, profound, and enduring communication.

The book includes valuable tools of the scholarly trade: musical examples, illustrations, figures, and tables provide clear evidence for the book's arguments, and appendixes identify musical sources and works that encourage further research and use in teaching. A criticism directed to the press would be of the editing. Small typographical errors distract the reader, and other issues suggest a lack of editorial involvement.