Would this be overstepping my boundaries?

[CCericola]

You can ask but it may not be up to them. Some music acts control the photography of their performances and use. For instance WKRP is hosting a concert for "Big Name Band". They grant you a pass to take photos but you can't do anything with them because the big band had the radio station sign contracts that all photography has to go through their management company. It can get confusing.

Just stick with local bands since you can't sell anything you take of musicians with large record labels behind them. Licensing images of celebrities is a whole other can of worms.