By the first decade of the 21st century, R&B had shifted towards an emphasis on solo artists with pop appeal, with Usher, Rihanna, and Beyoncé being the most prominent examples. Furthermore, the music was accompanied by aesthetically creative and unique music videos. Examples of these types of music videos include but are not limited to: Beyoncé's "Crazy in Love", Rihanna's "Pon de Replay", and Usher's "Caught Up". These music videos helped R&B become more profitable and more popular than it had been in the 1990s. The line between hip-hop and R&B and pop was significantly blurred by producers such as Timbaland and Lil Jon and artists such as Missy Elliott, T-Pain, Nelly, Akon and OutKast.