Everything fans now recognize as Jerry Seinfeld is right there in his June 5th, 1981, debut performance on The Tonight Show. The pippity-pap cadence, the exclamations, the unmistakable nasal tone and those tidy, carefully observed jokes that seek some happy common denominator in the audience. All that, plus he's got the peppy energy of youth. He evaluates the battle-readiness of the Swiss army, compliments a morbidly obese man who lost a couple hundred pounds and, in the most perfectly Seinfeldian bit, he considers the subtext of the "Left Turn Okay" traffic sign. "We're not crazy about you making the left, it's okay… get it over with," he says, and then adds a few more signs he hopes to see on the road, "Right Turn, Why Not? U-Turn, Enjoy It." Seinfeld's economy and precision aren't quite there yet, but it's more than enough to see the relief and delight break out in his face when road-tested material hits home here, knowing that it's changing the shape of his career on the spot.