Task: Question Answering
Input (English): Passage: Presley's rise to national attention in 1956 transformed the field of popular music and had a huge effect on the broader scope of popular culture. As the catalyst for the cultural revolution that was rock and roll, he was central not only to defining it as a musical genre but in making it a touchstone of youth culture and rebellious attitude. With its racially mixed origins—repeatedly affirmed by Presley—rock and roll's occupation of a central position in mainstream American culture facilitated a new acceptance and appreciation of black culture. In this regard, Little Richard said of Presley, "He was an integrator. Elvis was a blessing. They wouldn't let black music through. He opened the door for black music." Al Green agreed: "He broke the ice for all of us." President Jimmy Carter remarked on his legacy in 1977: "His music and his personality, fusing the styles of white country and black rhythm and blues, permanently changed the face of American popular culture. His following was immense, and he was a symbol to people the world over of the vitality, rebelliousness, and good humor of his country." Presley also heralded the vastly expanded reach of celebrity in the era of mass communication: at the age of 21, within a year of his first appearance on American network television, he was one of the most famous people in the world.Presley's name, image, and voice are instantly recognizable around the globe. He has inspired a legion of impersonators. In polls and surveys, he is recognized as one of the most important popular music artists and influential Americans. "Elvis Presley is the greatest cultural force in the twentieth century", said composer and conductor Leonard Bernstein. "He introduced the beat to everything and he changed everything—music, language, clothes. It's a whole new social revolution—the sixties came from it." In the words of John Lennon, "Nothing really affected me until Elvis." Bob Dylan described the sensation of first hearing Presley as "like busting out of jail".
On the 25th anniversary of Presley's death, The New York Times asserted, "All the talentless impersonators and appalling black velvet paintings on display can make him seem little more than a perverse and distant memory. But before Elvis was camp, he was its opposite: a genuine cultural force. ... Elvis' breakthroughs are underappreciated because in this rock-and-roll age, his hard-rocking music and sultry style have triumphed so completely." Not only Presley's achievements, but his failings as well, are seen by some cultural observers as adding to the power of his legacy, as in this description by Greil Marcus:. 
Question: What is the full name of the conductor that claimed the artist who was a catalyst for rock and roll was "the greatest cultural force in the twentieth century"?
Output (English): Leonard Bernstein.