E is a pretty easy note for guitarists to pull out of thin air. Especially a metal guitarist. I haven't verified that he actually sang an E, but my initial thought while watching it was "I think he's actually singing an E". I was in a singing group in college, and we sang one song so much, that started with a C, that I began to be able to produce C on demand. Not perfect pitch, but good pitch memory. I'd be more impresed if he could sing a G sharp on request, or something quite unrelated to E. If he has good relative pitch, which I don't doubt, he would be able to find most notes pretty quickly. Especially parts of the E triad. Anyhow.... Poor Fred just sort of has to sit there in these interviews, huh?