Slow day at work, I'm testing the knowledge of my coworker who is totally and completely removed from amything metal or rock (even though I got him addicted to Thunderstruck).
"Tell me a Led Zeppelin song"... and he mimed with his voice the riff and the initial line of Whole Lotta Love.
"Tell me a Deep Purple song"... and he mimes the riff of Smoke on the Water but couldn't remember the title.
"Difficult one, tell me a Black Sabbath song"... he didn't even try and gave up. I mumbled him Paranoid's riff, he doesn't know it.