I would keep the zoom you have for a while and add a macro and a fisheye, then later swap the zoom.
i have some extension tubes and i get great results with them for macro, not really into macro.... i have no interest in a fish eye lens.. i had a 10-20mm lens at one point.. not really my thing either.. more of a general shooting lens is what i am looking for. something that will be descent in low light thew out the whole focal range so something in 2.8 or f/4 is kind of ideal that is if F/4 would be a good choice i do not know.
i have some friends that play in bands. i would like to be able to get some good photos of them playing. there usually in some dark dingy bar.. not sure how well f/4 and my d7200 would do in that situation.. i have photographed them a time or two in the past quite a while ago but i used a flash.. more than likely the flash is not always gonna work. ill have to go out and shoot them with my lens set to 35mm ish where i can use it at f/4 some time and see how that works out.. that way ill know if a f/4 lens will do the trick or not..
What??????? Wait................................... your not following the Watchful Way of Photography, but doing your own thing???
If you are looking at dark indoor type things like bands in clubs etc., then an f2.8 would be the route I would go. Yes they are #1 expensive and #2 heavy, but they are also built like a tank, usually have the best optical quality and something that might mean something to you later on, they hold their resale value. 24-70 or 70-200 would be your call depending on the distances you are working with in your venues.