Well in regards to lens the problem is with your pocket, you really is limited.
If you are willing to get used lenses then you will have a bit more flexibility, ALL my lenses were bought used and I saved a lot of money this way.
Still the D7100 will take a nice slice of your budget, if you already have the 18-55mm lens then you have a basic all around kit lens, this means you can buy just the body and to that add one more lens.
I really cant recommend a good lens for you because a good lens will cost you, cost much more.
For street photography you said you have the 35mm which is a good lens, it will also be good for nigth photography.
For music I am assuming you mean concerts you might be able to get the 70-300mm VR which is a telezoom lens, I have this lens, for its price it is a fantastic lens, will give you a lot of reach and is very sharp, new its about 450$+tax, I got mine for 280$ used and I heard of people here who got it close to the 200$ mark.
Instead of the 18-55mm lens you can get the 18-105mm VR which will give you a better focal range and this lens is optically a bit better then the 18-55mm lens.
Good lenses are a bit of a problem, the good ones cost over a thousand dollard even used.
You can get a third party lenses but even those aint cheap and a bit more risky then the Nikon lenses as they might be a hit or mis with their CQ.
I have the Nikon D7100 and I build a good lens collection which matches my need.
For everyday general use I have the 24-85mm VR which is a very sharp lens, good focal range cost me 280$ used,
For walk around and Macro I have the 60mm 2.8G, very sharp and good lens which I also use for portrait 390$
For walk around, portrait and night photography I use the 50mm 1.4D sharp, sharp lens 170$
70-300mm VR is my telezoom, use this lens a lot, very flexible lens that covers a great range but good only for outside use 280$
I shared with your my lenses so you might also consider then, you have the prices I got them for so that might give you better understanding how much you can save and how happy I am with the lenses I have.
All my lenses are FX, I plan in the future to move to FX (full frame) camera so I am ready with my lenses, if you get a DX lens and plan in the future to upgrade to FX then you will have to sell these lenses so maybe concidering getting FX lenses right from the get go will save you future headache.
Good luck.