In this study, I explored how a high school English class’s multimodal project broadened student and teacher participation. Previous research has established that multimodal composing expands the nature of classroom texts, opens opportunities for identity expression, and extends access to audiences. Less is known about how affordances work together to increase options for more students and teachers to participate in school‐based writing. Informed by affinity space and multimodality frameworks, this article adds to a small pool of classroom affinity space studies. Through grounded theory analysis, findings reveal that a multimodal project provided students opportunities to participate as interactive audience members, pursue less typical routes to status, and express identity; their teacher experienced an opportunity to participate more flexibly. Pertinent to a rise in online learning and increasingly prevalent and complex ways to create multimodal content, findings illuminate classroom affinity space features focused on broadening participation.