Houston, singing again in “Sparkle.” (Alicia Gbur/Associated Press)

Sparkle” marks Whitney Houston’s first theatrical film role since she starred opposite Denzel Washington in 1996’s “The Preacher’s Wife.” It also, sadly, marks her final appearance in a movie.

Houston — the songstress who died in February at the age of 48 — is hardly the first star to posthumously appear onscreen. James Dean, Clark Gable, River Phoeniz, Brandon Lee, Bernie Mac, Aaliyah and Heath Ledger are among the many, many actors whose last cinematic efforts were not widely viewed until after their lives ended.

Sony has taken an appropriately restrained approach to marketing ”Sparkle” — a movie that opens Friday and received a two-and-a-half star review from Post critic Ann Hornaday — as Houston’s swan song. But certainly some may be compelled to see the remake of the 1976 girl-group drama primarily because of the late diva’s presence in it.

For reasons that some may characterize as human nature and others might view as a tad morbid, we are often intrigued to see the final pieces of work from a beloved performer, especially when that performer died very young.

In some cases, it’s because we want to bittersweetly affirm what we already knew: that the star in question possessed as much talent as we thought. In the cases of iconic figures like Dean — whose “Rebel Without a Cause” and “Giant” came out after he was killed in a car crash at age 24 — and Ledger, the posthumous force of nature in both “The Dark Knight” and “The Imaginarium of Doctor Parnassus” — that was certainly true.

Our reasons for wanting to see Houston in “Sparkle” — where she is again alive and vibrant if, as Hornaday suggests, somewhat vocally diminished — may have more in common with what motivated us to track Michael Jackson’s every dance move in the documentary “This Is It.”

Yes, we are eager to see Houston and Jackson croon and preen again, to see them strut their respective stuff. But given the unfortunate circumstances that surrounded both of their deaths, as well as the unflattering headlines that clouded the latter portions of their careers, we also watch these two films wanting to know: Were they okay?

Was Michael Jackson really frail in the days before his death, or was he still just as capable in his final hours of wowing us with his “Billie Jean” footwork? (The answer, it seems, was yes to both.)

And was Whitney Houston really in a place where she could have made a career comeback, if her personal demons and addictions had not tragically, as they so often did, stepped in her way?

Obviously, no movie can fully resolve those lingering questions. But for a couple of hours, a “This is It” or a “Sparkle” brings those pop music royals back to life for us. And for roughly two hours, their flickering images simultaneously and oddly remind us that they are both immortal and forever gone from the world that awaits us outside the multiplex.