In becoming one of the top-selling pop singers of all time, Whitney Houston's best-known songs were by design short and uplifting. The new documentary on her life and especially her death, "Whitney," is almost the polar opposite. It's long and ultra-depressing, but still quite compelling, too.

Obviously, a viewer knows going in that there won't be a happy ending. With hints of Houston's decline sprinkled throughout the two-hour movie, it also doesn't have much of a happy beginning. Or middle, either.

Even the nostalgic flashbacks to giddy, colorful MTV videos and early-'80s commercials at the start of the film — meant to take you back to the era of the singer's innocence-touting rise — are counterbalanced with bleak news snippets of Reagan inner-city poverty and drug abuse; a heavy-handed trick movie-wise, but a juxtaposition that does reflect Houston's life story.

"Whitney" is the work of Scottish filmmaker Kevin Macdonald, who crafted the excellent 2012 Bob Marley rock doc "Marley" after gaining fame with the 2006 drama "The Last King of Scotland." He earned top-tier access to family members and inner-circle employees, who are interviewed on screen amid clips of performances, home movies and interviews with Houston herself.

Macdonald even landed Bobby Brown. Unlike many of her admirably forthcoming family members, though, Houston's much-derided ex-husband doesn't say much. He clams up at the mere mention of her drug addictions, claiming it's not part of the story.

The drugs certainly play a big role here. A couple of the movie's talkers mention how troubled Houston was by the tabloid reports and TMZ-style gossip that followed the ups and downs of her marriage and her then-still-alleged drug abuse. But then the film goes down many of the same holes as the gossip hounds.

This is nothing new. Similar documentaries have explored the sad demises of Michael Jackson, Kurt Cobain, Jimi Hendrix and Amy Winehouse, and you can bet there will be one or more on Prince before too long.

One of the things that's applaudable about "Whitney" is that it gives her the rock-star treatment and puts her up there with the big boys. She's rightfully held up as one of the top-selling singers of her generation, one with unquestionably awesome talent and charisma. We're reminded of her groundbreaking on-screen biracial romance with Kevin Costner in "The Bodyguard" and the megahit it produced, "I Will Always Love You."

More of her greatness would have been a worthy addition to the film, along with more insight into her off-stage personality. But the movie drags on as is — as it tries to answer the simple question of, "What happened?" The answer, of course, is complex.

New allegations that Houston suffered sexual abuse from a family member as a child are brought up in the film. Old rumors that she may have been a closeted lesbian are also addressed (Houston's longtime confidante Robyn Crawford is the one person of note missing among the interviews). The pain of being sued by her once-close father is also deemed pivotal.

"Whitney" thoughtfully provides answers, including many hard ones, but it doesn't heal any wounds. At least her music can still serve that role.

@ChrisRstrib