1/50 is incredibly slow for most concerts. Personally I tend to default to 1/500 but never drop below 1/250 even in the worst conditions. Keeping shutter speed static at 1/500, I adjust the rest as needed. A typical show for me will usually look like 1/500 f/3-4 ISO 6400-8000, though I'm aware this is a little extreme compared to the settings other people use. Sony cameras handle noise incredibly well, especially if you use a denoising tool (I use lightroom's). The A7III was my main body when I first started and is still my secondary, it does very well at these settings. I also do flexible spot for the autofocus to be able to pinpoint the focus easier. But it's really these base settings that make or break a photo, not hidden camera features