Cecilia Aragon

The remaining four designers must create complementary looks for power couple Naya Rivera and Big Sean for his record release party.

For the first challenge, Rihanna tasks the designers with creating designs inspired by their favorite music artists. While some designers thrive with the creative freedom, others struggle to keep up with their first celebrity design challenge. The mentors are Pharrell Williams, Erin Wasson and Mel Ottenberg.

The designers create "off-duty" rock star looks for singer Carly Rae Jepsen; the winning look will be in a Glamour.com feature.

The cast creates looks inspired by old Hollywood glamour for Khloé Kardashian to wear at a Grammy Awards after-party. Recording artist Ne-Yo is guest mentor.

The designers pair up to create flashy stage looks for twin DJ sisters Liv and Mim, who are known as Nervo.

The six remaining designers create complementary stage looks for The Band Perry.