You may not know Lance Stack by name, but if you've been going to certain shows, you've probably seen his impressively portable, live recording setup. For over two years, Stack has been making high-quality recordings of live shows and posting them online. After getting a band's permission, he posts the tracks at his website, the Flat Response. A casual perusal of that site reveals a breathtaking treasure trove of live audio, including the kind of technical information any audio geek would want to know. By any standard, Stack's website is an important document of what's been going on in Denver music.