Though electronic song navigators were available, the primary way to find song selections for the Prologue 21 is through one of the available paper song catalogs. Several different versions were available by Sega, Clarion, and Taikan. Relatively early, the Clarion and Taikan versions appear to have been dropped, consolidating to a new version of the Sega catalog every few months that ran for over 40 volumes. Starting around 2007, catalogs were BMB branded after buying Sega Music Networks. Intermediate to new issues being published, monthly add-in pages would be available to adhere into the front section of the books with any new selections.
SEGA Prologue 21 