BURBANK, California (AP) — Guided by a thumping bass line from their backing band, the Jackson brothers strut forward to a row of four microphones, thrusting their pelvises along the way, before launching into "Can't Let Her Get Away," a song their superstar sibling released on his "Dangerous" album. If they had afros and matching powder blue suits, it might feel like 1977 again.

It doesn't. They're casually sporting sunglasses, workout gear and a few more pounds than when they, along with the future King of Pop, were simply known as the Jackson 5. (Also, "Can't Let Her Get Away" was released in 1991 after the group fizzled out.)

Nearly three years since Michael died while preparing for his comeback tour, four of his brothers — Marlon, Jermaine, Tito and Jackie — are set for their own return to the stage as The Jacksons. It hasn't been easy.

"The brothers don't know this, but I've broken down several times and cried during rehearsals," said Jermaine during a recent rehearsal break on a soundstage in Burbank, California. "I'm so used to Michael being on the right and then Marlon, Jackie, on and on. It's just something we never get used to."

The brothers are launching their "Unity" tour today, five days ahead of the third anniversary of Michael's death from an overdose of the anesthetic propofol on June 25, 2009.

"For me, this cycle that comes around every year — this day, that day — that doesn't affect me because it affects me every day," said Marlon. "When that day comes around, it's the same. You learn to live with it. I still wake up sometimes and go, 'Jeez. I can't believe my brother's not here.'"