Since 2002, Clément Vauchez and Thomas Couderc (Helmo) have shaped the visual identity of Jazzdor, Strasbourg’s improvised music festival. Originally a two-week event, Jazzdor has grown to include a Berlin festival (since 2007), a Strasbourg concert season (since 2014), a record label, and a Budapest edition (since 2023). This book explores 56 posters created by Helmo between 2019 and 2024, featuring insights from the designers and festival director Philippe Ochem. Using only a typeface and a trio of colors, Helmo embraces diverse visual languages—photography, drawing, painting, text—to mirror the range of musical aesthetics. The posters are also exhibited in Paris and Strasbourg.