A second track co-penned with Leslie, "Me & U," would be Cassie's first major hit. Sean "Puffy" Combs caught wind of the single and signed her to Bad Boy Entertainment. Her self-titled debut was released in the summer of 2006. Cassie peaked in the Top Three of the U.S. and U.K. R&B/hip-hop charts, as well as rising to number four on the Billboard 200. "Me & U" continued to climb the singles chart, peaking at number three and earning platinum certification. She also made her movie debut in Step Up 2: The Streets. Although she planned to record an immediate follow-up, those sessions never resulted in a proper studio album. Instead, Cassie released a series of high-profile collaborative singles over the ensuing years, including "Official Girl" with Lil Wayne in 2008; "Must Be Love" with Puffy and "Let's Get Crazy" with Akon in 2009; "Radio" with Fabolous and "Make You a Believer" with Jadakiss in 2011; and "Balcony" with Jeezy in 2012. That same year on Valentine's Day, Cassie issued the slick electro-dance track "King of Hearts," and later appeared on Nicki Minaj's single "The Boys."
In 2013, Cassie unveiled a new sound on her RockaByeBaby mixtape. Released in the spring, the effort — her first major work in seven years — marked a dark and mature shift for the singer. Inspired by the classic '90s flick New Jack City, RockaByeBaby featured a cover showing Cassie holding a golden pistol and songs that combined raw grit and adult content with her strong vocals. A stacked roster of guests appeared on the album, including Wiz Khalifa, Pusha T, French Montana, Rick Ross, Jeremih, Fabolous, Meek Mill, Ester Dean, and Too $hort, as well as production nods from Mike WiLL Made-It and Rob Holladay. After starring in Honey 3: Dare to Dance and The Perfect Match in 2016, Cassie announced that she had signed with Epic Records. The G-Eazy collaboration "Love a Loser," her first single for the major label, was released in 2017. Beginning in 2019, Cassie delivered a steady stream of singles including "Excuses," "Don't Let Go," "Teach Me," and "Simple Things." ~ Neil Z. Yeung