Hello
As @SidV say’s , the content are the king .
Also give it some time (months) for see some results . Right now , the social networks , like FB , in my opinion , are gaining a lot of “ground” , general speaking people are very vague and prefer to be in fb groups all day than to go through any community or forum. it’s going to be very difficult, I’m in the same problem as you, I do not know whether to become a community of DJs or a general community / debates.
This is a fundamental problem and it is likely the reason that the OPs community isn’t taking off.
Communities aren’t things that you should just decide to create. You need to create them to satisfy an existing need. i.e. you need to do extensive research of your prospective audience to establish what it is that they can’t currently solve with existing communities or resources. It won’t just work because you decide to make it.
For instance, I’m an amateur DJ but I’m not going to join your community just because it’s there. I already get all the tracks and advice that I need from my existing DJ community. You need to have a point of difference so that you offer something that people can’t ge elsewhere.
Culture is key here, you have to create a small group of active users and build your culture with them
Culture and good content draw people, not just activity.
You have to invest into building intrinsic motivations and not extrinsic.
Invest your time in people, not in badges
Just my 2 cent