Please explain in simple terms...brightness

Could someone please explain what some adjectives mean? I'm reading descriptions such as brightness and transparent, but I have only a basic knowledge of sound qualities. Is there a website to educate myself in this area?

I listen to classical, opera, and jazz, and my room size is 12x20. Currently I own a simple system: Yamaha components (CD, Tuner, and Amp.), with a pair of Kipsch (RF-5) floorstanders. It was a drastic improvement from what I lived with before, but I'll need better sound because I'm not hearing the "color", or is it "brilliance" in the voices, especially when a choir is heard. Maybe I'm not doing my speakers justice with the Yamaha components, however I anticipated upgrading those at some point.

Now I'm planning on overhauling my whole system, and from what I've read, I'll need to give myself plenty of time to experiment and research what's best for my situation.

One thing I couldn't get over were those high-hats coming from the Tractix horn; I'd swear there was an actual drummer sitting between the speakers if I closed my eyes.

Thanks for all the knowledge that's shared here.

David (Hftd, CT)