The Gadioc

I have the Nikon D90 and looking to get the lens with suitable premises for concerts. repost again srry. comments appreciated?
AF-S Nikkor 50mm f/1.4G objective is looking, but have looked at Sigma 28-70mm F2.8 EX DG. What is the ideal target. Srry for post again i kinda screwed another Chris thnx
For me, [...]