My 2¢:
Set the video button to ISO.
Set one of the front buttons to the auto ISO menu.
Get used to the need for more button/dial combos than the bigger models.
I usually shoot concerts with spot metering and AF point on the faces.
Experiment with the highlight protected spot metering. I am still not sure whether it works well or not.
Since the D750 I shoot manual with auto ISO.
For concerts typically ISO 1600 - ISO 6400 (ISO 12K only in seriously bad light).
Shutter speed 1/200-1/250, unless the band is really frozen or very active.
Since the D750 the need to fix WB to tungsten for concerts has diminished in my eyes. Auto WB works quite nicely (if you want color).
Get a portrait grip (third party works just fine).
That gives you a second battery which is always online. Though I have yet to need a second battery for a concert even though I did reach more than 1K shots.
And it gives you a better grip for portraits in my eyes, let alone a better grip for large hands.
I run my D750 with 2 64G cards, the second working as a backup. Gives you more than 1000 shots in 14bit compressed.
Depending on the type of access you have and the views you want to capture, you might want to try life view with a 45° tilted screen and then shoot over the head of the crowds. Not a hight keeper rate, but a different perspective. I am usually tall enough to shoot over the crowds without that ;-), but even for me the higher vantage point is sometimes useful.
cheers
afx
