Of all the pop stars who have attempted to act, Chers track record is arguably the best. Silkwood. Mask. The Witches of Eastwick. Moonstruck. Mermaids. If These Walls Could Talk.

As her post-Sonny & Cher solo career waxed and waned in the 80s and early 90s, Chers movie career flourished a true achievement, given the ostentatious displays that had made her a walking glitter bomb since the mid-60s. Shedding her eccentricities in a way that many pop stars cannot, Cher was able to transform onscreen time and again, so much so that she won an Oscar after uttering one of the most quotable lines in cinema history.

But when Cher out-glittered herself in 1998 with her mammoth Believe comeback, her acting career atrophied. At 52, her diva status had become mythological, even a bit comical. She was too decadent to disappear into the same down-home movie roles, and Hollywood no longer saw her as a profitable actress. Cher played along with the joke, though, portraying exaggerated versions of herself (see: The Player, Will & Grace, Stuck on You) even when she wasnt actually playing herself (see: Burlesque).

That tradition continues today. Cher is the grande dame of the new Mamma Mia! Here We Go Again , making a flamboyant eleventh-hour entrance that only someone of her renown could pull off. (She plays Ruby, a famous singer who has a thorny relationship with her daughter Donna, portrayed by Meryl Streep.)

But as we relish Chers septuagenarian divadom, its easy to forget how we got here. We got here because Cher commanded maximum respect at a critical time in her career, challenging anyone who assumed her pop panache would prevent her from becoming a great actress capable of playing everyday women experiencing everyday struggles.

So lets revisit just how Cher became the greatest pop-actor of them all, and why she maintains that superlative even if shes graduated from Hollywoods leading-lady graces.