Emmy-nominated costume designer Lou Eyrich took something of a leap when she walked out of the cheery halls of the fictional McKinley High in “Glee” and into the grimy world of Briarcliff Manor Sanitarium, a hospital for the criminally insane that serves as the centerpiece for “American Horror Story: Asylum” on FX. Tattered, soiled, and bloody hospital uniforms from 1964 are a far cry from show-choir sequins.

But Eyrich, who has been working with “Horror Story” creators Ryan Murphy and Brad Falchuk since the 1990s, had a chance to dive back into costuming a choreographed number on the Jan. 2 episode of “Horror Story.” Jessica Lange, who plays fallen nun Sister Jude, performs “The Name Game” during a hallucination. The swinging ’60s-inspired clip has become a minor Internet sensation. We talked with Eyrich about Lange’s channeling of Dusty Springfield, as well as dressing the nuns and patients of Briarcliff.