A terminal apparatus is connectable to a host station and is responsive to a command to execute an application program to treat music data. In the terminal apparatus, a local storage locally stores an old version of software containing music data and various application programs which are selectively executed to treat the music data. An interface is optionally activated prior to execution of an application program for communication with the host station having a remote storage which remotely stores a new version of software including music data and various application programs which are made available latest by the host station. A controller operates when the interface establishes the communication with the host station for downloading the new version from the remote storage of the host station and for transferring the downloaded new version to the local storage so as to renew the old version stocked in the local storage by the new version. A processor responds to the command for selectively executing the various application programs to treat the music data based on the new version when the interface has been activated and otherwise for selectively executing the various application programs to treat the music data based on the old version when the interface has not been activated. A display graphically presents a map containing various objects corresponding to the various application programs. A pointing tool is manipulated for pointing one of the various objects on the display so as to select one of the various application programs corresponding to the pointed object to thereby input the command.