Question: Who successfully "crossed over" to pop music and was one of the most influential, successful and acclaimed vocalists of the 20th century, who released an EP on April 20, 1962 ?

full_context: Document 1: Patsy Cline's Greatest Hits: Patsy Cline's Greatest Hits is a compilation consisting of American country pop music singer, Patsy Cline's greatest hits. The album consists of Cline's biggest hits between 1957 and 1963. It is one of the biggest selling albums in the United States by any female country music artist.
Document 2: Songs by Patsy Cline: Songs by Patsy Cline is an EP released by American country music singer, Patsy Cline on August 5, 1957. It was Cline's first released EP collection.
Document 3: Sentimentally Yours: Sentimentally Yours is the third studio album by American country music singer, Patsy Cline, released August 7, 1962. The album was the final studio album Cline would release before her death in a plane crash less than a year later. (Her last album was recorded in 1963
Document 4: Showcase (Patsy Cline album): Showcase is a studio album by American country music singer Patsy Cline, recorded with The Jordanaires and released November 27, 1961. It was Cline's second studio album and her first since "Patsy Cline" in 1957.
Document 5: Here's Patsy Cline: Here's Patsy Cline is the third compilation album of music originally recorded by American country artist, Patsy Cline. The album consists of selected material Cline had recorded during her years at Four Star Records.
Document 6: Jean Shepard discography: American country artist Jean Shepard released twenty-five studio albums, fifteen compilation albums, one live album, seventy-one singles, two charting B-sides, and appeared on nine albums. Signing in 1952 with Capitol Records, her second single "A Dear John Letter" (a 1953 duet with Ferlin Husky) became a breakthrough hit. It topped the "Billboard" Hot Country Songs for six weeks and reached the Billboard Hot 100's fourth position. Shepard's solo career became successful in 1955 with the release several singles, including the top-five hits "A Satisfied Mind" and "Beautiful Lies". Shepard's debut studio album "Songs of a Love Affair" (1956) was the first country music "concept album" to be issued. She was commercially unsuccessful until a major comeback in 1964 with the top-five hit "Second Fiddle (To an Old Guitar)" and the studio album "Lighthearted and Blue". The latter was her first to reach the Top Country Albums list. A series of hit singles continued for Shepard, such as "Many Happy Hangovers to You", "I'll Take the Dog", "If Teardrops Were Silver", and "Then He Touched Me". Accompanying albums reached the major positions on the country albums chart, including "Many Happy Hangovers", "Heart We Did All That We Could", and "Best by Request".
Document 7: Country Soul: Country Soul contains recordings of a prestardom Glen Campbell, which were made around 1960-1961. This album, just like the other Starday album Country Music Star No. 1, was released after Glen Campbell rose to international fame with hits like "Gentle on My Mind," "By the Time I Get to Phoenix" and "Wichita Lineman." Campbell sued against these releases but eventually settled with Starday.
Document 8: She's Got You (EP): She's Got You is an EP released by American country music singer, Patsy Cline on April 20, 1962. It was the second EP Cline released in that year.
Document 9: The Patsy Cline Story: The Patsy Cline Story is a double compilation album consisting of American country music singer Patsy Cline's best-known songs between 1961 and 1963. The album was released on June 10, 1963, three months following Cline's death.
Document 10: Patsy Cline: Patsy Cline (born Virginia Patterson Hensley; September 8, 1932 – March 5, 1963) was an American country music singer. Part of the late 1950s/early 1960s Nashville sound, Cline successfully "crossed over" to pop music and was one of the most influential, successful and acclaimed vocalists of the 20th century. She died at the age of 30 in a multiple-fatality crash of the private plane of her manager, Randy Hughes.
Document 11: Hawkshaw Hawkins: Harold Franklin Hawkins (December 22, 1921 – March 5, 1963), better known as Hawkshaw Hawkins, was an American country music singer popular from the 1950s into the early 1960s known for his rich, smooth vocals and music drawn from blues, boogie and honky tonk. At 6 ft 5 inches tall, he had an imposing stage presence, and he dressed more conservatively than some other male country singers. Hawkins died in the 1963 plane crash that also killed country stars Patsy Cline and Cowboy Copas. He was a member of the Grand Ole Opry and was married to country star Jean Shepard.
Document 12: Patsy Cline (1961 EP): Patsy Cline is an EP released by American country music singer, Patsy Cline on August 14, 1961. It Cline's third EP to be released.
Document 13: Patsy Cline (album): Patsy Cline is a studio album by American country music singer, Patsy Cline, released on August 5, 1957. This was the debut album by Cline and would be one of three studio albums Cline would record during her lifetime.
Document 14: (You Got) The Power of Love: The Everly Brothers recorded "(You Got) The Power of Love", written by Delaney Bramlett and Joey Cooper, in Hollywood on February 3, 1966. Session artists included Glen Campbell, Larry Knechtel, Jim Gordon and Hal Blaine. Released by Warner Brothers as a single in April 1966, this rock and roll tune was a cohesive effort and remains a favorite today. The song featured on the "In Our Image" album subsequently released by Warner Brothers, one of a trio of albums regarded by Don Everly as the best they recorded for the Warner Brothers label, the other two being "Rock N Soul" and "Beat N Soul".
Document 15: Patsy Cline (1957 EP): Patsy Cline is an EP released by American country music singer, Patsy Cline on August 5, 1957. It was Cline's first EP released through Decca Records, as her previous was released under Coral Records, a Decca subsidiary.
ground_truth: Patsy Cline