Robert Waller (musician)

Robert Waller, also known as EST, is an American rapper and songwriter. He began his career as a member of Philadelphia-based hip hop collective Three Times Dope, who signed with Arista Records in the late 1980s. Waller then became known for his production and songwriting work, having contributed to the Destiny's Child album Destiny Fulfilled (2004), which was nominated for Best R&B Song at the 48th Annual Grammy Awards in 2006 with "Cater 2 U". He also worked with the group's lead member Beyoncé on her solo debut, Dangerously in Love (2003).