I want to share some what I thought as pretty decent results from a show I went to last week. I was shooting with a Sony A5100 with a 7Artisan 25mm f1.8 MF lens. I didn't have credential or anything but they didn't care I had a camera so I got to use it at a decent spot that I was at. Definitely not a concert photographer so this was purely for fun. No viewfinder and MF means I was mainly relying on the focus peaking feature to get focus and using ISO3200-5000 to get enough shutter speed. DxO did the heavy lifting in post on the noise. Gotta say I am pretty impressed with the $74 lens...
Pics look nice! I'm always a fan of throwing someone from the crowd in the frame of my own concert photos like you did in #5. Creates a good negative space and I like the dynamic of depicting the crowds presence at the show.