Here is an example of Arista Premium 400 (reputedly Tri-X) as shot indoors at Boston TD Garden
1/125
f/4.5

This was developed in Adox Adonal (Original Rodinal formula) 1:100 stand for 70 minutes.

I'm not sure what the lighting was at your concert. Probably not as much light but maybe comparable. I estimated I was going for something between 6400 and 12000 -- basically just trying to get anything at all.

Image: https://dl.dropbox.com/u/7447315/celts_125-0008.jpg

Good luck!