Abstract: Write-once read-many disks have a directory for file management in every session and files existing in other sessions can be managed in this directory. For write-once read-many disks for music use, however, there is no directory for file management and it has been impossible to access a session and reproduce music in other session. The present invention enables music CDs to take full advantage of multisession recording and realizes multisession-formatted music CDs wherein TOCs (Table of Contents) are recorded in the lead-in areas of the multiple sessions, each TOC in which the information for managing pieces of music (tracks) in other sessions has been registered.