the background vocals, giving just Gaye and Terrell vocal dominance. The song became a crossover pop hit in the spring of 1967, reaching No. 19 on the Billboard Hot 100 and No. 3 on the R&B charts and making Terrell a star. Their follow-up, "Your Precious Love", became an even bigger hit, reaching No. 5 on the pop chart and No. 2 on the R&B chart. At the end of the year, the duo scored another top-ten single with "If I Could Build My Whole World Around You", which peaked at No. 10 on the pop chart and No. 2 on the R&B chart. The song's B-side, the Marvin Gaye composition "If This World Were Mine", became a modest hit on both charts (No. 68 pop, No. 27 R&B). Gaye would later cite the song as "one of Tammi's favorites". All four songs were included on Gaye and Terrell's first duet album, United, released in the late summer of 1967. Throughout that year, Gaye and Terrell began performing together and Terrell became a vocal and performance inspiration for the shy and laid-back Gaye, who hated live performing. The duo also performed together on television shows to their hits. They were voted the No. 1 R&B duo in Cash Box magazine's Annual Year-End Survey in 1970. Cancer diagnosis While Terrell was finally being established as a star, the migraines and headaches she had suffered from childhood were becoming more constant. While she complained of pains, she insisted to people close to her that she was well enough to perform. However, on October 14, 1967, while performing "Your Precious Love" with Gaye at Hampden–Sydney College, just outside the town of Farmville, Virginia, Terrell collapsed into Gaye's arms onstage. Shortly after returning from Virginia, doctors diagnosed a malignant tumor on the right side of her brain. She underwent brain surgery at Graduate Hospital in Philadelphia on January 13, 1968. After recovering from her first surgery, Terrell returned to Hitsville studios in Detroit and recorded "You're All I Need to Get By". Both that song and "Ain't Nothing Like the Real Thing" reached No. 1 on the R&B charts. Despite Terrell's optimism, her tumor worsened, requiring more surgeries. By 1969, Terrell had retired from live performances as she had been ordered by doctors not to perform due to her tumors. Motown issued Terrell's first and only solo album, Irresistible, in early 1969. Terrell was