Our jukebox is used in two rooms and each room has its own remote control. Having two remote controls is something of a luxury because the jukebox could work just as well with only one. The same music is plays in each room, so it would be perfectly feasible, though less convenient, to carry the remote control from room to room as required.

Having two remote controls has additional benefits:

1. When designing and writing the software it's possible to set the two remote controls up differently and do side-by-side comparisons.
2. If one remote control were to break or have its batteries totally discharged, we wouldn't be without music.

The two remote controls can browse the music database simultaneously and independently. But for pages concerned with the music currently playing or queued, things are not so simple. When the user of one remote control alters the state of the player (play/pause/stop, previous/next track, add/delete track(s), etc), the display of the other remote control isn't immediately updated. The server has no way to update one remote control when changes are made by the other remote control. However each remote control does update its displays from the server whenever the user clicks on anything (almost anything, anyway), and the "Player" and "Queue" parts of the display refresh themselves automatically every minute even if no-one clicks on anything. In practice, we find that out-of-date displays on remote controls are not a problem.

The CGI programs are written in such a way that simultaneous commands from both remote controls are acted on in an orderly way. So if, for instance, two users click on "Play Now" at exactly the same time, the jukebox will play one user's choice of album, not the two albums interleaved.

The browser on my main PC is effectively a third remote control, and all that I've written on this page about a second remote control applies to that as well. There's no reason not to have four remote controls, or in fact any reasonable number of remote controls.