Grammy-winning pop diva Whitney Houston died Saturday at 48. Her voice inspired generations of musicians, and her death in a Beverly Hills hotel on the eve of the 2012 Grammy Awards triggered an outpouring of grief.

Michael Baker became Houston's drummer in the early 1990s, and went on to become her musical director. A close friend of Houston's for the last 18 years of her life, he says he remembers traveling on tours with crews of 80 to 100 people, and says it was almost like a big family.

"Whitney knew the back-line people, she knew the people that were in the back doing the back-of-the-stage work, she knew the people that were rigging, she knew who the stage managers were," Baker tells NPR's Neal Conan.

Matthew Garrison, who played bass for Houston on her final tour in 2009 and 2010, says that everyone was important to the singer.

"I was just amazed by, I would say, her insight into the actual process of preparing the music," Garrison says. He says he remembers a particular rehearsal where she was able to identify — out of a group of five or six singers — who was singing one wrong note.

"It was such an amazing thing that she could basically hone in, in the middle of this big band playing," Garrison says. "There were strings, there was the bass and the drums and the guitars, and she picked out this one little note."

During that final tour in support of her 2009 album I Look to You, Houston struggled to hit high notes and stay on key. Baker said her vocal struggles were similar to a sports injury.

"She gave it 100 percent every single night," Baker says. "She never once said, 'Hey, look guys, I can't sing tonight.' My job at that point was to do everything in my ability to help her get through the shows."

Garrison has been surrounded by music for most of his life. His father, Jimmy Garrison, played bass for jazz musician John Coltrane. He said that touring with Houston taught him important lessons about life on the road.

"What I've taken away from the experience is dealing with human relationships and how to handle that process," Garrison says. "What we did was we took care of each other."

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