If there's a term which musicians have been throwing around lately when theorizing on attracting audiences, it's "Multimedia".
"We should be using multimedia! There should be something for people to look at!" Yes, but remember that all of this adds all sorts of extra crazy. I am all for making a concert more than the norm but I am tired of hearing people throwing this word around.
If you're going to slip this neat little word into your next conversation, take a look at these few points first.
Firstly, if producing a concert is difficult enough for you, adding lighting equipment or a screen or what have you is too much for you to handle. Moreover, you would definitely need someone to do the tech side during the event.
Secondly, adding a whole new dimension to the concert requires as much planning/practice as the music portion. You can't bring in a pyro and ask him to 'wing it' to Rachmoninov's Prelude in C sharp minor.
Thirdly, there must be some theory that interconnects whatever you've got going on. If there are pictures rotating on the screen, are they trying evoke something? Is that something compatible with the music? Are they displaying something connected to the music in history? Etc., etc.
You may think I'm going over the top here, but trust me. It is very easy for something like this to come off as a 'stunt' rather than an elevated experience. For example: The National Arts Center Orchestra did a screening of the Fellowship of the Ring last July while doing the full score live with, they boast, a 200-piece orchestra and choir. While I think this would be quite cool to go see (mainly because the audience was asked to attend in costume), it's quite a risk to put on a show which, for all intents and purposes, could be recreated at home. `Hell, I could call my buddies over, get dressed up, and we could take a drink every time Sam says, "Mr. Frodo". Obviously you and I don't have the kind of cash to blow on a show like that, but we shouldn't catch ourselves producing something which audiences might find elsewhere.
Finally, is there really nothing better you can do with the programming, the performing, and/or the staging first? If there is anything I've learnt here so far, it's that there is so much more to a concert than the music.
More on that last point later.
Good, you've made it through my little grumble. Are you still keen on the big "M"? Go ahead, then, use it but beware, it's a pandora's box you're opening. Well, that's a bit harsh. It's a combination of a happy meal and pandora's box. But definitely more proportion of evil than happy.