Singers are the ones who have to be especially careful about what they eat/drink right before a show. It's not just a diva thing. Smile What you consume can really effect your performance. Though it is going to vary some from person to person.
Yeah, and its amazing what some professional singers will do to their cords before performances. I work at a road house that hosts large tours and big name concerts. I think my favorite rider hospitality quote was a recent one this spring where, in reference to the bottle of wine that must be in the dressing room before the show, quote "If you're spending less than $50, you're not trying hard enough" [to find a good local brand].
We just had a tour in recently that had so much insence going, both in their dressing room and onstage, that I 1 - was smoked out of my own office, and 2 - am now worried how I'm going to get the smell out of the sofa from that dressing room. How on earth could they even breathe, let alone sing, with 30 sticks of insense burning on the drum riser, I still don't know. I was allergic to the stuff and spent most of the show hiding in the box office.
Its been really interesting seeing the hospitality riders that come with the big name bands. And to see what they'll eat right before going onstage. Often there's good things asked for in the rider, like throat-coat tea, but then after the show you find it unopened in the dressing room. Then other times the onstage beverage station will be all alcohol.
On most shows, there's a deal with the in house catering company, I make the coffee on the dock [for the union] and they make the coffee in the catering kitchen [for everyone else]. There's one promoter who's too cheap to pay for the union to have coffee, so cheap in fact that the one time he brought donuts for them, they were day-old stale things leftover from somewhere. But their only choice is caffenated, and while there is hot water for tea, they have to bring their own tea in.
The broadway tours either have their own stuff that the prop department sets up, or they order the in house catering. Its all been very eye-opening though.
-Centaura