In the episode, Jane Lynch (as Sue Sylvester) re-created Olivia Newton-John’s “Physical” video, first in a solo version that is leaked to YouTube by the glee clubbers and, later, in a reputation-saving duet with the Australian pop sweetheart and “Grease” star herself. Molly Shannon also made her first guest appearance in the recurring role of Brenda Castle, an alcoholic, pill-popping mess of a new astronomy teacher who turns out to be the only person who can intimidate the formidable Sue.

Tony Award nominee Jonathan Groff (Spring Awakening) continued his recurring role as suspicious new star performer Jesse St. James, and Tony nominee Stephen Tobolowsky (Morning’s at Seven) briefly returned as disgraced former glee club director Sandy Ryerson. In addition to “Physical,” songs performed included “Ice Ice Baby,” “U Can’t Touch This,” “Run Joey Run” and “Total Eclipse of the Heart.”

Next week’s episode, “Laryngitis,” will feature a welcome dose of show tunes in its musical lineup, including “The Lady Is a Tramp,” “One” and “Rose’s Turn,” as well as the pop hits “Jessie’s Girl” and “The Boy Is Mine.”

Thomas Peter