I've done a few of these over the years.
--Styx (several incarnations and certain band members individually, including wives)
--Damn Yankees (ditto, spinoff of sorts of above)
--Sammy Hagar (working w/ a DJ from an Arkansas station)
--Meat Loaf (was working for the bass player at the time)
--assorted other performers both classic and recent at festival shows
One of the key things I learned right off the bat is that the after-show (or pre-show, in Hagar's case) is every bit as much a performance as what you see on stage. It's like a special "closer look". At various times I've done unofficial fanzines, worked with radio stations and booking agents, and done websites for people, so my contact was more business than fan-based most of the time.
I didn't put much stock in being witty, etc. "Dude, great show, looking forward to the next record" etc etc is plenty. Other times (ie, radio stuff) it was, "Dude, can you do a station line for us?"
So my approach to backstage has always been, "Get in, get the job done, get out, and go home." That and "drop me an email when you're ready for updates."
Adrienne
(all biznizz.....)
