Initially standard equipment with the Prologue 21, but early on were switched to an option that operating locations could purchase additionally. Song Navigators were one of the earliest electronic song selectors available with Japanese karaoke machines. Instead of browsing through a book that would constantly need updated with additional pages every month and could become damaged over time, these rechargeable tablets allowed customers to search through and select available songs electronically.
Song navigators and their corresponding charger are manufactured by NEC for Sega Music Networks.
SEGA Prologue 21 