Question: David Michael Letterman (born April 12, 1947) is an American television host, comedian, writer, and producer. He hosted a late night television talk show for 33 years, beginning with the February 1, 1982, debut of Late Night with David Letterman on NBC, and ending with the May 20, 2015, broadcast of Late Show with David Letterman on CBS. In total, Letterman hosted 6,028 episodes of Late Night and Late Show, surpassing friend and mentor Johnny Carson as the longest-serving late night talk show host in American television history. In 1996 Letterman was ranked 45th on TV Guide's 50 Greatest TV Stars of All Time.

In 1975, encouraged by his then-wife Michelle and several of his Sigma Chi fraternity brothers, Letterman moved to Los Angeles, with hope of becoming a comedy writer. He and Michelle packed their belongings in his pickup truck and headed west. As of 2012, he still owned the truck. In Los Angeles, he began performing comedy at The Comedy Store. Jimmie Walker saw him on stage; with an endorsement from George Miller, Letterman joined a group of comedians whom Walker hired to write jokes for his stand-up act, a group that at various times would also include Jay Leno, Paul Mooney, Robert Schimmel, Richard Jeni, Louie Anderson, Elayne Boosler, Byron Allen, Jack Handey, and Steve Oedekerk.  By the summer of 1977, Letterman was a writer and regular on the six-week summer series The Starland Vocal Band Show, broadcast on CBS. He hosted a 1977 pilot for a game show entitled The Riddlers (that was never picked up), and co-starred in the Barry Levinson-produced comedy special Peeping Times that aired in January 1978. Later that year, Letterman was a cast member on Mary Tyler Moore's variety show, Mary. Letterman made a guest appearance on Mork & Mindy (as a parody of EST leader Werner Erhard) and appearances on game shows such as The $20,000 Pyramid, The Gong Show, Hollywood Squares, Password Plus and Liar's Club, as well as the Canadian cooking show Celebrity Cooks (November 1977), talk shows such as 90 Minutes Live (February 24 and April 14, 1978), and The Mike Douglas Show (April 3, 1979 and February 7, 1980). He was also screen tested for the lead role in the 1980 film Airplane!, a role that eventually went to Robert Hays.  His dry, sarcastic humor caught the attention of scouts for The Tonight Show Starring Johnny Carson, and Letterman was soon a regular guest on the show. Letterman became a favorite of Carson and was a regular guest host for the show beginning in 1978. Letterman credits Carson as the person who influenced his career the most.

Using a quote from the above article, answer the following question: What did he do as part of the group?
HHHHHH
Answer: Walker hired to write jokes for his stand-up act,

Problem: Steven Noel Wariner was born on Christmas Day of 1954 in Noblesville, Indiana. Influenced at an early age by George Jones and Chet Atkins, Wariner started performing in his father's band, and later moved on to playing in local clubs. By age 17, he had been hired by Dottie West as a bass guitarist, and played on her single "Country Sunshine". He also worked with Glen Campbell, who he has cited as a major influence on his work.

1991 saw the release of Wariner's first album for Arista Records. Entitled I Am Ready, this was also the first album of his career to be certified gold for shipping 500,000 copies in the United States. Singles from it included "Leave Him Out of This", "The Tips of My Fingers" (a cover of Bill Anderson's 1960 single), "A Woman Loves", "Crash Course in the Blues" and "Like a River to the Sea". These first three singles were all Top 10 hits. In 1992, Wariner received his first Grammy Award, for Best Country Vocal Collaboration, as a guest vocalist and guitarist alongside Vince Gill, Ricky Skaggs and fiddler Mark O'Connor on the single "Restless", a No. 25-peaking single from O'Connor's album The New Nashville Cats. He also collaborated with O'Connor on the No. 71-peaking "Now It Belongs to You" on the same album.  His second album for Arista was 1993's Drive. Leading off this album was the Top 10 "If I Didn't Love You". After it came the Top 30 hits "Drivin' and Cryin'" and "It Won't Be Over You", although the album's title track stopped at No. 63. Wariner, along with Lee Roy Parnell and Diamond Rio, recorded a cover of Merle Haggard's "Workin' Man's Blues" as the fictional band Jed Zeppelin for the late-1994 tribute album Mama's Hungry Eyes: A Tribute to Merle Haggard. This cover peaked at No. 48 and was made into a music video. A year later, Wariner contributed a cover of the song "Get Back" to Come Together: America Salutes The Beatles, a tribute album which included country music covers of songs by The Beatles. His rendition charted at No. 72 on the country charts and was also a music video shot primarily at Union Station in Nashville.  An instrumental album, No More Mr. Nice Guy followed in 1996. His final Arista release, it produced no singles, although one of the tracks, "Brickyard Boogie", was nominated for Best Country Instrumental at the 1997 Grammy Awards. This track was a collaboration with Bryan White, Jeffrey Steele, Bryan Austin and former Pearl River guitarist Derek George. Despite exiting Arista in 1997, Wariner made a guest appearance along with Mac McAnally in the music video for Sawyer Brown's 1997 single "This Night Won't Last Forever", a cover of the Michael Johnson song.

What did he win this Grammy for?

Answer with quotes:
for Best Country Vocal Collaboration,