An electronic device comprising: receiving means for receiving a first packaged installation file; installation means for installing a first version of a software application using the received first packaged installation file; packaging means for creating a second packaged installation file, for installing a second version of the software application; and transfer means for transferring the second packaged installation file to a second host device. A hand-portable electronic device, for sending data to another device during a session to enable the interactive production of music by the devices as an ensemble, comprising: output means operable, during a session, to send musical synchronisation information to the other device; a user input for controlling, during a session, the content of at least one of first musical control data and musical synchronisation information; and a synthesiser for producing music in dependence upon the first musical control data and the musical synchronisation information.