Chris Brown Upset He Can't Move on from His Past, Says Source

Chris Brown's latest album F.A.M.E. may signify a new beginning for him, but the singer can't seem to avoid questions about pleading guilty to felony assault against ex-girlfriend Rihanna almost two years ago.

Brown, 21, who lost his temper Tuesday morning after an interview on Good Morning America with Robin Roberts in which she asked about Rihanna, "is upset" by what transpired on the show, a source tells PEOPLE.

"He's been trying to move on from his past and focus on his music, and he's finally putting out an album," the source says. "Why can't we focus on that? He makes great music and he loves his fans. He's a good kid."

Even before the live GMA segment, another source says rehearsals were "tense," at one point causing Brown to "flip out" even before his appearance.

But his tone shifted later, and Brown took to Twitter to talk up his album and praise his fans. "Thank you to everyone who supports my music!!!" he wrote. "Key Word (music) !!! Love y'all."

This came in response to an outpouring of support from fans. "The media is just trying to bring you down," one Brown devotee Tweeted. "DON?T LET THEM!!!!!"

Brown, who continued the promotional rounds and continued Tweeting on Tuesday afternoon, also received Twitter love from fellow hip-hop artists, including Diddy and Keri Hilson.

"Yall go out & get my boy @chrisbrown's new album 'F.A.M.E' in stores TODAAAAY!!!" Brown's "Superhuman" collaborator Hilson wrote. "His talent is undeniable. I'm proud of you, CB!! Love you!"

� Reporting by LIZ MCNEIL

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