In 1993, Winfrey hosted a rare prime-time interview with Michael Jackson, which became the fourth most-watched event in American television history as well as the most watched interview ever, with an audience of 36.5 million. On December 1, 2005, Winfrey appeared on the Late Show with David Letterman to promote the new Broadway musical The Color Purple, of which she was a producer, joining the host for the first time in 16 years. The episode was hailed by some as the "television event of the decade" and helped Letterman attract his largest audience in more than 11 years: 13.45 million viewers. Although a much-rumored feud was said to have been the cause of the rift, both Winfrey and Letterman balked at such talk. "I want you to know, it's really over, whatever you thought was happening", said Winfrey. On September 10, 2007, Letterman made his first appearance on The Oprah Winfrey Show, as its season premiere was filmed in New York City.  In 2006, rappers Ludacris, 50 Cent and Ice Cube criticized Winfrey for what they perceived as an anti-hip hop bias. In an interview with GQ magazine, Ludacris said that Winfrey gave him a "hard time" about his lyrics, and edited comments he made during an appearance on her show with the cast of the film Crash. He also said that he wasn't initially invited on the show with the rest of the cast. Winfrey responded by saying that she is opposed to rap lyrics that "marginalize women", but enjoys some artists, including Kanye West, who appeared on her show. She said she spoke with Ludacris backstage after his appearance to explain her position and said she understood that his music was for entertainment purposes, but that some of his listeners might take it literally. In September 2008, Winfrey received criticism after Matt Drudge of the Drudge Report reported that Winfrey refused to have Sarah Palin on her show, allegedly because of Winfrey's support for Barack Obama. Winfrey denied the report, maintaining that there never was a discussion regarding Palin's appearing on her show. She said that after she made public her support for Obama, she decided that she would not let her show be used as a platform for any of the candidates. Although Obama appeared twice on her show, those appearances were prior to his declaring himself a candidate. Winfrey added that Palin would make a fantastic guest and that she would love to have her on the show after the election, which she did on November 18, 2009.  In 2009, Winfrey was criticized for allowing actress Suzanne Somers to appear on her show to discuss hormone treatments that are not accepted by mainstream medicine. Critics have also suggested that Winfrey is not tough enough when questioning celebrity guests or politicians whom she appears to like. Lisa de Moraes, a media columnist for The Washington Post, stated: "Oprah doesn't do follow-up questions unless you're an author who's embarrassed her by fabricating portions of a supposed memoir she's plugged for her book club."

Answer this question "Did she appear on his show more then once?" by extracting the answer from the text above.
On September 10, 2007, Letterman made his first appearance on The Oprah Winfrey Show, as its season premiere was filmed in New York City.