Quite simple really........They're NOT always empty!
First off let me be clear of MY personal definition of 'Modern Soul' here, it's nothing made in the seventies, nothing made in the eighties, maybe a little bit of ninties but definitely music made in the noughties, all tempos, all styles, Indie, Southern, Soulful Garage but SOULFUL through voice or vibe. If you accept that definition and are not expecting to hear Charles Johnson or Driza Bone, then you need to visit Prestwich (two rooms Northern and Modern) where the 'Modern' room is packed EVERY month. Then if that's not enough try Stoke this weekend (Two Rooms Nothern and Modern) the Modern Room was very busy last time and will be again on Saturday. Failing that try BURY on the 19th (two rooms Northern and Modern) cause that'll be a busy Modern Room as well. If you cant make any of them then maybe you could try Fleetwood Marine Hall on the 27th (two rooms Northern and Modern) and the Modern Room will be FAR from empty there.
These gigs are just off the top of my head and demonstrate that the 'Modern' Rooms as described in the initial post are far from empty.
QED
BazM