Obama tweeted that she dropped in at the Grammys to support Keys.
Obama's initial comments were interrupted by raucous applause and many in the Staples Centre crowd stood.
Michelle said, "Music helps us share ourselves, our dignity and sorrows, our hopes our joys". It helps us to hear one another, to invite each other in.
Folk singer Brandi Carlile, 37, took three early Grammys while an absent Ariana Grande, who pulled out of the show last week after a dispute with producers, won her first Grammy, best pop vocal album for "Sweetener". "Is it OK I can't wait to see you?"
Fans were so refreshed by the awe-inspiring, controversy-free award show that many even asked Keys if she would step in and host the Oscars, saving it from its host-less confusion. "I'm in tears with honor and gratitude", she wrote on Twitter after her first win. "Music shows us that all of it matters".
On the red carpet awards for best dressed will surely go to Miley Cyrus in her pared back black suit or Lady Gaga's silver ruffled number.
Performing a medley of songs by various artists including Jay-Z, Kings Of Leon and Nat King Cole during the ceremony, Keys lived up to her name as she performed the mash-up while managing to play TWO pianos simultaneously.
Grammy organisers this year expanded the top four categories - album, record, song of the year, and best new artist - to eight nominees from five in a bid to diversify the contest. Childish Gambino, despite not attending the show, won both Record and Song of the Year for "This Is America", the first ever rap song to win either of those awards. But presenters, John Mayer and Alicia Keys, had to accept the award for the absent rapper.