A preview of next week’s all-Madonna episode of “Glee” — with Sue Sylvester starring in “Vogue!”

One thing I especially love about this show is is agnosticism about music — it makes no distinction between classic rock (“Somebody to Love”), Broadway show tunes (“Defying Gravity”), 60’s pop (“Don’t Make Me Over”), or current hits (“My Life Would Suck Without You”). I love the mash-up episodes, combining songs like “Smile” (Lily Allen) with “Smile” (composed some 80 years earlier by Charlie Chaplin). It is a hallmark of adolescence to be exclusionary and to define people by what they like, with absolute and rigid categories for indie, metal, emo, and especially NOW vs. THEN. So I am very happy to see this show not just introduce its audience to music they may have thought of as outside their sphere but to the very idea of openness to great songs, wherever they come from.