Step aside winners. The Grammy Awards have long belonged to performers and unexpected moments – and this year's show was no different with Kanye West rushing the stage, Madonna's burlesque homage to bullfighting, and both Pharrell and Beyonce referring to the death of Mike Brown in Ferguson.

Kristen Wiig made a surprise appearance and stole the show during Sia's performance of Chandelier. The Bridesmaids star pulled off possibly the best kept secret of the 2015 Grammys with her cameo alongside teen dancer Maddie Ziegler as Sia sang obscured in the background.

Grammy awards 2015 best photos
Kristen Wiig and Maddie Ziegler dance to Sia's Chandelier as the artist stands with her back to the audienceLucy Nicholson/Reuters
Grammy awards 2015 best photos
Sia and dancer Maddie Ziegler arrive at the Grammy AwardsMario Anzuoni/Reuters

Kanye West, in perhaps a tongue-in-cheek gag on his infamous outburst rushing the stage in protest at the 2009 MTV Video Music Awards, approached album of the year winner Beck on stage before flashing a quick grin, waving his hand and retreating.

Grammy awards 2015 best photos
Kanye West tries to upstage Beck after he won album of the year for Morning PhaseLucy Nicholson/Reuters

Madonna's burlesque homage to bullfighting raised a few eyebrows. Pop music's 56-year-old grand dame of scandalising spectacle performed her new song Living for Love in red and black lingerie with 20 dancers wearing bulls' horns and rhinestone-covered faces twirling her about.

Grammy awards 2015 best photos
Madonna performs Living for LoveKevork Djansezian/Getty Images
Grammy awards 2015 best photos
Madonna flashes her bum on the Grammys red carpetJason Merritt/Getty Images

Pharrell Williams, dressed as a hotel bellboy in shorts, recast his uptempo international smash Happy as a soaring orchestral song with Chinese concert pianist Lang Lang, film composer Hans Zimmer on guitar and a choir of 20.

But the singer-producer's allusions to the protest chant "hands up, don't shoot" and hooded sweatshirts about the killings of unarmed black teens cast the shadow of civil rights, the predominant theme at the show's close.

Grammy awards 2015 best photos
Pharrell performs Happy dressed as a bellhopLarry Busacca/Getty Images for NARAS
Grammy awards 2015 best photos
Beyoncé closes the show with Take My Hand Precious Lord as a group of background performers hold up their hands in a "hands up, don't shoot" stanceRobyn Beck/AFP

The show took a serious turn with President Barack Obama delivering a taped address urging the audience and TV viewers to help stop domestic violence, through the ItsOnUs.org campaign.

Then Brooke Axtell, a survivor of domestic abuse, took the stage urging victims of abuse to seek help and telling her own story about how her ex-boyfriend had threatened to kill her. Katy Perry finished the segment with the anthem By the Grace of God.

Grammy awards 2015 best photos
Katy Perry performs By the Grace of GodKevork Djansezian/Getty Images

British soul singer Sam Smith was the night's big winner, with four Grammys including record and song of the Year for his anthem Stay With Me. He was also anointed best new artist and his debut album In The Lonely Hour won best pop vocal album.

"I want to thank the man who this record is about, who I fell in love with last year," Smith said as he accepted his gramophone-shaped trophy for record of the year. "Thank you so much for breaking my heart because you got me four Grammys."

Grammy awards 2015 best photos
Sam Smith poses with his Grammy awards for best new artist, best pop/vocal album for In the Lonely Hour and song of the year and record of the year for Stay With MeMike Blake/Reuters
Grammy awards 2015 best photos
"Weird Al" Yankovic poses with the award for best comedy album for Mandatory FunMike Blake/Reuters
Grammy awards 2015 best photos
Brian Johnson and Angus Young of AC/DC perform a medley of songs to open the showLucy Nicholson/Reuters
Grammy awards 2015 best photos
Paul McCartney embraces Rihanna after performing FourFiveSeconds with Kanye West Lucy Nicholson/Reuters