OK fair enough, in that case I'd go for something along the lines of this:
PCPartPicker part list:
http://pcpartpicker.com/p/mBh3Jx
Price breakdown by merchant: http://pcpartpicker.com/p/mBh3Jx/by_merchant/
CPU: Intel Core i7-4790K 4.0GHz Quad-Core OEM/Tray Processor ($322.99 @ SuperBiiz)
CPU Cooler: Cooler Master Hyper TX3 54.8 CFM Sleeve Bearing CPU Cooler ($19.89 @ OutletPC)
Motherboard: Gigabyte GA-H97-D3H ATX LGA1150 Motherboard ($88.99 @ SuperBiiz)
Memory: Mushkin Stealth 16GB (2 x 8GB) DDR3-1600 Memory ($81.99 @ Newegg)
Storage: Samsung 850 EVO 250GB M.2-2280 Solid State Drive ($118.98 @ Newegg)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($76.99 @ Newegg)
Video Card: EVGA GeForce GTX 970 4GB FTW ACX 2.0 Video Card ($324.99 @ NCIX US)
Case: Fractal Design Define R5 (Black) ATX Mid Tower Case ($89.99 @ Newegg)
Power Supply: SeaSonic 660W 80+ Platinum Certified Fully-Modular ATX Power Supply ($134.99 @ NCIX US)
Total: $1249.80
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-07-21 11:53 EDT-0400
An i7 is only going to give small gains over an i5 in games but will be a lot better in the music stuff as well, seems worth it at your budget, especially as you don't want to overclock. The aftermarket cooler is overkill for you but the CPU is like $30 cheaper without the crappy stock cooler for some reason so you might as well have a decent one. The small size of the TX3 guarantees compatibility with PCI-e slots, that's why I went for that over a bigger cooler.
16GB RAM seems worth it because you have a lot of mods and will help with the music software.
That motherboard is just good value. Doesn't support overclocking but you don't want to do that anyway.
The SSD is on the new M.2 port so should be super speedy and last a long time. I imagine 250GB should be plenty of space for Windows and your programs, the HDD is for photos/videos/music and other general storage.
The GTX 970 is great value for gaming, it should crush any game at 1080P and still stand up pretty well in 1440P as well. Considering you don't want to upgrade for a while, it may be worth considering the GTX 980Ti if you plan on playing at 1440P.
You seem to like the R5, hence the choice of case. The cooling is pretty decent and there's plenty of space in it as well.
It seems like a good idea to go for an absolute top notch PSU considering you want long term stability and reliability. That is one of the best PSUs on the market. The wattage is total overkill but gives you loads of headroom for any future upgrades.
If you have any questions about any of that, let me know.