hi John, would it be the first 7 seconds of a track? this could be a pain for tracks which don't start straight away or ones which start slowly? Can you really get the info you need from a 7 second preview?? Maybe if it could play the chorus of tracks it could be helpful,but i myself don't see a 'Need' for it.
None the less.... they've got it on the new Sound Leisure Venue Hub Jukebox.