Somebody on the shop floor says they have heard the same song twice this morning. They are usually right, and the cause is almost never the size of the music folder. It is that shuffle has no memory of what it played an hour ago.
Shuffle picks at random, and random is clumpier than people expect. With no memory of what played earlier, nothing stops the same track coming round twice in an hour, or three songs by one artist arriving together. Staff who hear the system all day notice the clusters long before a visitor does, and a duplicated file quietly doubles its own chances.
Separation rules are the memory shuffle lacks. They are three numbers: do not play the same track within so many minutes, do not play the same artist within so many minutes, and do not repeat anything within the last so many tracks. Three hours, forty-five minutes and twenty tracks are sensible starting points, and every station in the country runs some version of them.
Here a music product and a building one part company. With a small library the rules will eventually forbid everything, and the honest answer is that they must give way rather than let the speakers fall silent. Multilarm relaxes them in a fixed order - artist window, then track window, then all repeat rules, least-recently-played first - and logs every relaxation so nothing is hidden.
Silence on a PA is a fault. A repeated artist is a Tuesday.
Point it at your audio folders and it builds an index, reading the title, artist, album, genre, year and length already in your files without modifying any of them. Then build playlists and turn the rotation on. There are four steps, and only the third is new to anybody who has run background music before:
Announcements still duck the music, and an emergency still stops it - the rotation only decides what plays when nothing more important is happening.
Run the library reports before you touch the rules. Four of them answer the questions that matter: what is unreadable, what has no title or artist, what is clipped and sounds harsh on a PA, and what is duplicated. Duplicates are the usual culprit behind "that song again", because two copies of one track get two chances every time.
Does a bigger music folder fix the repetition?
Less than people expect. Shuffle has no memory, so a thousand tracks still produce clusters, and a duplicated file doubles its own chances. Separation rules fix the pattern; more music only dilutes it.
What happens if the rules leave nothing to play?
The rules give way, in a fixed order: the artist window first, then the track window, then all repeat rules, least-recently-played first. Every relaxation is written to the log. Silence on a PA is a fault; a repeated artist is not.
Can I drop a jingle or a reminder in every so often?
Yes. An interrupting playlist fires on a count or a clock - every twenty tracks, or every thirty minutes, optionally only between set hours - which is how a station ident, a safety reminder or a closing-time notice is normally run.
Do I need an internet radio product to do this?
Only if you are broadcasting to the internet. LibreTime and AzuraCast are built for stations with public listeners, and Multilarm does not stream to Icecast at all. For music on speakers inside one building, the rotation is the part you actually need.
Does Multilarm supply the music?
No. It plays files you already hold or a stream you already subscribe to, and it keeps a play log you can export in the shape PRS, PPL and SoundExchange returns ask for. Whether a licence is needed, and which, is between you and the licensing society.