Question: When did the artist of "Rock 'n' Roll Million Sellers" success begin to wane?

full_context: Document 1: Conny Van Dyke: Conny Van Dyke (sometimes credited as Connie Van Dyke) is a singer and actress, born September 28, 1945 in Nassawadox, Virginia to Benjamin and Charlotte Elizabeth Van Dyke.
Document 2: Connie Smith singles discography: The singles discography of Connie Smith, an American country artist, consists of 48 singles and two B-sides. After signing with RCA Victor Records in 1964, Smith released her debut single in August entitled "Once a Day". The song topped the "Billboard Magazine" Hot Country Singles chart by November and held the position for eight weeks, to date being the longest running song at number one by a female country artist. The single's success launched Smith into stardom, making Smith one of the decade's most successful female artists. The follow-up single "Then and Only Then" reached #4 on the country singles chart, while its flip side ("Tiny Blue Transistor Radio") went to #25 on the same chart. All of Smith's singles released between 1965 and 1968 reached the top 10 on the "Billboard" country songs chart, including "If I Talk to Him", "Ain't Had No Lovin'", and "Cincinnati, Ohio". By 1969 Smith felt highly pressured from her career and cut back on promoting singles. Smith's chart success slightly declined because of this, with songs like "Ribbon of Darkness" (1969) and "Louisiana Man" (1970) only reaching the top 20. Other singles continued to peak within the top 10 including "I Never Once Stopped Loving You" (1970) and "Just One Time" (1971).
Document 3: Cher: Cher ( ; born Cherilyn Sarkisian; May 20, 1946) is an American singer and actress. Sometimes referred to as the Goddess of Pop, she has been described as embodying female autonomy in a male-dominated industry. She is known for her distinctive contralto singing voice and for having worked in numerous areas of entertainment, as well as adopting a variety of styles and appearances during her five-decade-long career.
Document 4: Jerry Lee Lewis discography: This is a detailed discography for American rock and roll, country, and gospel singer-songwriter Jerry Lee Lewis. One of the pioneers of rockabilly, Lewis has recorded over 40 albums in a career spanning seven decades. Lewis is a versatile artist, and has recorded songs in multiple genres. Lewis, in 1986, was one of the very first inductees into the Rock and Roll Hall of Fame, and, as of 2017, is the last surviving rock and roll pioneer of Sun Records (fellow Sun rock and roll colleagues such as Elvis Presley, Johnny Cash, Roy Orbison, and Carl Perkins, among others, are deceased.) Some of his best known songs are "Great Balls of Fire", "Whole Lotta Shakin' Goin' On", and "High School Confidential". His album, "Live at the Star Club, Hamburg", is widely considered one of the greatest live concert albums ever. In his lengthy career in music, Lewis has had 30 songs reach the top ten on the "Billboard Country-and-Western" chart. Lewis is regarded as one of the greatest and most influential pianists of the rock and roll era, and was ranked number 24 on "Rolling Stone" magazine's list of the "100 Greatest Artists of All Time".
Document 5: Rosanne Cash discography: The discography of Rosanne Cash, an American singer-songwriter, consists of thirteen studio albums, six compilation albums, one tribute album, and 39 singles. The daughter of Johnny Cash, Rosanne Cash recorded her self-titled debut album in 1978 under the German label Ariola. After signing with Columbia Records in 1979, Cash's second studio album "Right or Wrong" was released. Its lead single "No Memories Hangin' Around" (a duet with Bobby Bare) reached the Top 20 on the "Billboard" Hot Country Songs chart. Cash's third studio release, "Seven Year Ache" (1981) gained major success when the title track peaked at number one on the "Billboard" Country chart, followed by "My Baby Thinks He's a Train" and "Blue Moon with a Heartache," which also reached the top spot. The album's follow-up effort, "Somewhere in the Stars" (1982) produced two Top 10 hits on the "Billboard" chart. After a 3-year hiatus, Cash issued "Rhythm & Romance" in 1985, which reached #1 on the "Billboard" Top Country Albums list. It spawned four Top 10 singles. This included the number one single, "I Don't Know Why You Don't Want Me," which won the Grammy Award for Best Female Country Vocal Performance in 1986. Her sixth album, "King's Record Shop" was released in 1987. The album peaked at number six on the country albums chart and certified gold in the United States. The four singles released from "King's Record Shop" all reached number one on the "Billboard" Country chart between 1987 and 1988, including a cover of Johnny Cash's "Tennessee Flat-Top Box."
Document 6: Connie Francis: Connie Francis (born Concetta Rosa Maria Franconero, December 12, 1938) is an American pop singer and top-charting female vocalist of the late 1950s and early 1960s. Although her chart success waned in the second half of the 1960s, Francis remained a top concert draw. Despite several severe interruptions in her career, she is still active as a recording and performing artist.
Document 7: Frank Sinatra: Francis Albert Sinatra ( ; ] ; December 12, 1915 – May 14, 1998) was an American singer, actor, and producer who was one of the most popular and influential musical artists of the 20th century. He is one of the best-selling music artists of all time, having sold more than 150 million records worldwide. Born in Hoboken, New Jersey, to Italian immigrants, Sinatra began his musical career in the swing era with bandleaders Harry James and Tommy Dorsey. Sinatra found success as a solo artist after he signed with Columbia Records in 1943, becoming the idol of the "bobby soxers". He released his debut album, "The Voice of Frank Sinatra", in 1946. Sinatra's professional career had stalled by the early 1950s, and he turned to Las Vegas, where he became one of its best known performers as part of the Rat Pack. His career was reborn in 1953 with the success of "From Here to Eternity", with his performance subsequently winning an Academy Award and Golden Globe Award for Best Supporting Actor. Sinatra released several critically lauded albums, including "In the Wee Small Hours" (1955), "Songs for Swingin' Lovers!" (1956), "Come Fly with Me" (1958), "Only the Lonely" (1958) and "Nice 'n' Easy" (1960).
Document 8: Connie Smith: Connie Smith (born Constance June Meador; August 14, 1941) is an American country music artist. Active since 1964, Smith is widely considered to be one of the genre's best female vocalists. She has earned 11 Grammy award nominations, 20 top ten "Billboard" country singles, and 31 charting albums, three of which have hit number one. On October 21, 2012, Smith became the 12th solo female vocalist and 19th woman to be elected to the Country Music Hall of Fame. Smith has an estimated net worth of $18 million.
Document 9: Julie London discography: The discography of Julie London, an American Jazz artist, consists of twenty nine studio albums, one live album, five compilation albums, two additional albums, and twenty-nine singles. After a moderately successful film career, London signed a recording contract with the newly formed Liberty Records in 1955. Her debut single "Cry Me a River" reached number nine on the Billboard Hot 100 in 1955. In June 1957, it would also peak at number twenty-two on the UK Singles Chart. "Cry Me a River" became London's most successful and highest-selling single of her musical career. The single would sell three million copies in total. Her debut studio album "Julie Is Her Name" was issued in December 1955 and reached the second position on the Billboard 200 albums chart. London's next three studio releases, "Lonely Girl" (1956), "Calendar Girl" (1956), and "About the Blues" (1957), reached the top-twenty of the Billboard 200 survey as well.
Document 10: Patti Page: Clara Ann Fowler (November 8, 1927 – January 1, 2013), known by her professional name Patti Page, was an American singer of traditional pop music and country music. She was the top-charting female vocalist and best-selling female artist of the 1950s, selling over 100 million records during a six-decade long career. She was often introduced as "the Singin' Rage, Miss Patti Page". New York WNEW disc-jockey William B. Williams introduced her as "A Page in my life called Patti".
Document 11: Rock 'n' Roll Million Sellers: Rock 'n' Roll Million Sellers is a studio album recorded by American entertainer Connie Francis. It was issued on the Contour label (2870 383) as "Connie Francis Sings the Million Sellers".
Document 12: Rock 'n' Roll (John Lennon album): Rock 'n' Roll is the sixth studio album by John Lennon. Released in 1975, it is an album of late 1950s and early 1960s songs as covered by Lennon. Recording the album was problematic and spanned an entire year: Phil Spector produced sessions in October 1973 at A&M Studios, and Lennon produced sessions in October 1974 at Record Plant Studios (East). Lennon was being sued by Morris Levy over copyright infringement of one line in his song "Come Together". As part of an agreement, Lennon had to include three Levy-owned songs on "Rock 'n' Roll". Spector disappeared with the session recordings and was subsequently involved in a motor accident, leaving the album's tracks unrecoverable until the beginning of the "Walls and Bridges" sessions. With "Walls and Bridges" coming out first, featuring one Levy-owned song, Levy sued Lennon expecting to see Lennon's "Rock 'n' Roll" album.
Document 13: Patti Page: Clara Ann Fowler (November 8, 1927 – January 1, 2013), known by her professional name Patti Page, was an American singer of traditional pop music and country music. She was the top-charting female vocalist and best-selling female artist of the 1950s, selling over 100 million records during a six-decade long career. She was often introduced as "the Singin' Rage, Miss Patti Page". New York WNEW disc-jockey William B. Williams introduced her as "A Page in my life called Patti".
Document 14: Connie Francis and The Kids Next Door: Connie Francis and The Kids Next Door is a studio album recorded by U. S. Entertainer Connie Francis.
Document 15: Donna Summer: LaDonna Adrian Gaines (December 31, 1948May 17, 2012), better known by her stage name Donna Summer, was an American singer, songwriter, and painter. She gained prominence during the disco era of the late 1970s. A five-time Grammy Award winner, Summer was the first artist to have three consecutive double albums reach No. 1 on the United States "Billboard" 200 chart and charted four number-one singles in the U.S. within a 12-month period. Summer has reportedly sold over 140 million records worldwide, making her one of the world's best-selling artists of all time. She also charted two number-one singles on the R&B charts in the U.S. and a number-one in the U.K.
ground_truth: the second half of the 1960s