Platinum by the RIAA. To date the album has sold over 3 million copies in the US. In Canada, the album was certified gold by Music Canada for 50,000 copies in shipments. In 2014, Vibe magazine estimated that the album had sold six million copies globally. Upon its release, Age Ain't Nothing But a Number received generally favorable reviews from music critics. Some writers noted that Aaliyah's "silky vocals" and "sultry voice" blended with Kelly's new jack swing helped define R&B in the 1990s. Her sound was also compared to that of female quartet En Vogue. Christopher John Farley of Time magazine called the album a "beautifully restrained work", noting that Aaliyah's "girlish, breathy vocals rode calmly on R. Kelly's rough beats". Stephen Thomas Erlewine of AllMusic felt that the album had its "share of filler", but described the singles as "slyly seductive". He also wrote that the songs on the album were "frequently better" than that of Kelly's second studio album, 12 Play. The single "At Your Best (You Are Love)" was criticized by Billboard for being out of place on the album and for its length. Aaliyah's debut single, "Back & Forth", peaked at number 5 on the Hot 100 and topped the Hot R&B/Hip-Hop Songs chart for three weeks. Two more singles charted: a cover of the Isley Brothers' "At Your Best (You Are Love)" peaked at number 6 on the Billboard Hot 100, and the album's title track, "Age Ain't Nothing but a Number", peaked at number 75. Additionally, she released "The Thing I Like" as part of the soundtrack to the 1994 film A Low Down Dirty Shame. 1996–2000: One in a Million and Romeo Must Die In 1996, Aaliyah left Jive Records and signed with Atlantic Records. She worked with record producers Timbaland and Missy Elliott, who contributed to her second studio album, One in a Million. Elliott recalled Timbaland and herself being nervous to work with Aaliyah, since Aaliyah had already released her successful debut album while Elliott and Timbaland were just starting out. Elliott also feared she would be a diva, but reflected that Aaliyah "came in and was so warming; she made us immediately feel like family." The album yielded the lead single "If Your Girl Only Knew", which peaked at number 11 on the Billboard Hot 100 and topped the Billboard Hot R&B/Hip-Hop Songs for two weeks. It also generated