Problem: Background: Cher (; born Cherilyn Sarkisian (Armenian: Sherilin Sargsyan); May 20, 1946) is an American singer and actress. Sometimes called 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 six-decade-long career.
Context: At age 16, Cher dropped out of school, left her mother's house, and moved to Los Angeles with a friend. She took acting classes and worked to support herself, dancing in small clubs along Hollywood's Sunset Strip and introducing herself to performers, managers, and agents. According to Berman, "[Cher] did not hesitate to approach anyone she thought could help her get a break, make a new contact, or get an audition." Cher met performer Sonny Bono in November 1962 when he was working for record producer Phil Spector. Cher's friend moved out, and Cher accepted Sonny's offer to be his housekeeper. Sonny introduced Cher to Spector, who used her as a backup singer on many recordings, including the Ronettes' "Be My Baby" and the Righteous Brothers' "You've Lost That Lovin' Feelin'". Spector produced her first single, the commercially unsuccessful "Ringo, I Love You", which Cher recorded under the name Bonnie Jo Mason. Cher and Sonny became close friends, eventual lovers, and performed their own unofficial wedding ceremony in a hotel room in Tijuana, Mexico, on October 27, 1964. Although Sonny had wanted to launch Cher as a solo artist, she encouraged him to perform with her because she suffered from stage fright, and he began joining her onstage, singing the harmonies. Cher disguised her nervousness by looking at Sonny; she later commented that she sang to the people through him. In late 1964, they emerged as a duo called Caesar & Cleo, releasing the poorly received singles "Do You Wanna Dance?", "Love Is Strange", and "Let the Good Times Roll". Cher signed with Liberty Records' Imperial imprint in the end of 1964, and Sonny became her producer. The single "Dream Baby", released under the name "Cherilyn", received airplay in Los Angeles. Encouraged by Imperial, Cher worked with Sonny on her second solo single on the label, a cover version of Bob Dylan's "All I Really Want to Do", which peaked at number 15 on the U.S. Billboard Hot 100 in 1965. Meanwhile, the Byrds had released their own version of the same song. When competition on the singles charts started between Cher and the Byrds, the group's record label began to promote the B-side of the Byrds' single. Roger McGuinn of the Byrds commented, "We loved the Cher version ... We didn't want to hassle. So we just turned our record over." Cher's debut album, All I Really Want to Do (1965), reached number 16 on the Billboard 200; it was later described by AllMusic's Tim Sendra as "one of the stronger folk-pop records of the era".
Question: when did the solo career start?
Answer: Cher signed with Liberty Records' Imperial imprint in the end of 1964, and Sonny became her producer.

Background: Enrique Martin Morales (born December 24, 1971), commonly known as Ricky Martin, is a Puerto Rican singer, actor and author. Martin began his career at age 12 with the all-boy pop group Menudo. After five years with the group, he released several Spanish-language solo albums throughout the 1990s. He also acted on stage and on TV in Mexico, where he achieved modest stardom.
Context: After achieving modest fame in Puerto Rico for his work in television commercials, Martin auditioned for membership in the Puerto Rican boy band Menudo. Although the executives enjoyed his dancing and singing at his first two auditions, Martin was rejected because he was too short. By the third audition, his persistence impressed executives, and in 1984, 12-year-old Martin became a member. A month after joining Menudo, he made his debut performance with the group at the Luis A. Ferre Performing Arts Center in San Juan. During this performance, he inadvertently disobeyed the choreography by walking around the stage, when it was planned that he would stay still, and was chastised by the band manager after the show: "The mistake was such a big deal that from that moment on, never again did I move when I wasn't supposed to move...That was the discipline of Menudo: You either did things the way you were told or you were not part of the group." The song "Asignatura Pendiente" from Almas del Silencio (2003) was inspired by the first time Martin left Puerto Rico to tour with Menudo. Although Martin enjoyed traveling and performing onstage with Menudo, he found the band's busy schedule and strict management exhausting, and later reflected that the experience "cost" him his childhood. He considered leaving the group while on tour in Brazil, but ultimately decided to stay out of fear of media backlash and being sued for breach of contract. Martin also began struggling with his sexuality, noting the stark contrast between his status as a sex symbol and his own emotions. Despite this, Martin acknowledged his "opportunity to have so many amazing experiences with so many amazing people" during his time with the group. He developed an interest in philanthropy when the group became UNICEF ambassadors, often working with impoverished children in third world countries. His experiences as an ambassador affected him greatly and inspired him to continue working with charities later in life. By 1987, Menudo's record sales began to decline, and the group changed its image, adopting an edgier look and performing more rock-influenced songs. The band released the album Somos Los Hijos del Rock in Spanish, and to appeal to the Menudo's Filipino fanbase, the group released In Action, recording songs in both English and Tagalog. After recording 11 albums with the group, Martin left Menudo in July 1989, at age 17, hoping to rest and evaluate his career path. He performed his final show with the group at the same venue where he'd performed his first performance as a member. Martin returned to Puerto Rico to graduate from high school, and 13 days after turning 18, he moved to New York City to celebrate his financial independence; since he was a minor during his time as a member of Menudo, Martin was not allowed to access his own bank accounts. He was accepted into New York University's Tisch School of the Arts, but months before classes began, Martin dropped out and moved to Mexico City to perform in the play Mama Ama el Rock (Mom Loves Rock).
Question: When was Ricky Martin in Menudo?
Answer:
1984, 12-year-old Martin became a member.