Continuous music on S Series

We have a few clients that have a set of 3 to 5 minute messages they use for MoH.
These messages basically advertise the other services the company offers.

I have converted these into WAV files that the PBX can play but it always plays from the beginning of the track.

It would be good to have the tracks playing on the system so when the caller was placed on hold, they would hear the track playing as if it was continually streaming from an outside source.

Currently the most anyone hears of these messages is the first 30 seconds or so because it always starts from the beginning.