There are a couple other options for you. Try this: Play with a more open vowel sound...as in "taww" Play a bit softer, with a smoother attack Think darker thoughts. Breathe in big and open and relaxed. Think something in German. Bright and dark are descriptors that refer, actually, to the amount of which type of overtones are present in your sound. Bright= more highs; dark= more lows. Sort of like the treble and bass controls on a stereo or a graphic equalizer. Sound is a very personal issue. We all work very hard to achieve the sound we think is the ideal. Sometimes, however, it is necessary to alter your sound to suit the piece. Is this what your director might be alluding to? I really like chocolate. I love chocolate with raspberry, especially. (Call it a weakness!). But, I also really enjoy chocolate and peanut butter ice cream. It depends on the mood I'm in, I guess. I also really like garlic. But I'd never, ever, mix garlic, chocolate and raspberry in the same dish. Let's go a step further: I also really enjoy coffee. There are so many different kinds, and they offer different characteristics to the trained palette. I'm still learning, but am beginning to be able to distinguish a few characteristics. Some are very light, and feel high and light on the tongue. They don't stand up well to a good piece of chocolate cake, but they are very nice with something a bit lighter or fruity. A richer, darker and more robust flavor that has darker overtones and maybe fuller body stands up better to that piece of blackout cake; the lighter just would not do. But it might overpower a lighter more fluffy dessert. See? I wonder if your director just might be asking for something a bit different...maybe trying to push your envelope a bit and testing your abilities. If he/she is constantly on you about it, then my guess would be not; but if it's this one instance, for this solo, in this context, maybe?