Taylor Swift featured two of pop's biggest stars during her fifth and final sold-out 1989 show at LA's Staples Center last night. Longtime musical crush Justin Timberlake performed "Mirrors" — his first on-stage appearance since he and Jessica Biel welcomed their first child in April. Best friend Selena Gomez joined Taylor on stage for the live debut of "Good for You." But the third and most surprising guest had never done arena shows before, just coffee shop sets. For the first time since Friends, Lisa Kudrow—as Phoebe Buffay, natch—sang "Smelly Cat." Taylor tried singing some parts, though not without some advice from Phoebe herself: "You have to really feel the lyrics." Watch highlights from their cameos below.