I can make myself sound exactly like Grace Slick by using a simple reverb trick. What I do is lightly and rapidly karate chop my neck when I sing certain words. Like when I am singing the part 'when the truth is found to be lies' I do the karate chop thing on the word lies and I get that famous Grace Slick reverb sound. If you were to close your eyes while I'm doing it you would think Grace Slick is in the room. Cheers!