Just a day before her anticipated show at Super Bowl 50, pop megastar Beyonce has released an unexpected single. The song, called Formation, features a cameo from her husband, Jay-Z, and daughter, Blue Ivy.

There was speculation the star would play two half-time songs for fans at the Super Bowl later today. It seems a duet with Coldplay, Hymn For the Weekend, will now be followed up with the new song – Beyonce’s first major release since 2013.

The single itself has been released for free on the streaming service Tidal, owned by rapper and producer husband Jay-Z. In return for the free track, downloaders will need to provide an email address.

Beyonce helped build publicity for the new single by posting several pictures on Instagram. The images show a group of dancers in a line, and a shot of the star hanging out of the window of a car, her braids dangling down the side.

In the lyrics to the song, Beyonce addresses celebrity, race and injustice in America. The video is set in New Orleans, Louisiana and in one scene ‘Queen Bey’ can be seen standing on top of a floating police car.

The single was co-written with Swan Lee of rap group Rae Sremmurd and has been released with two cuts. The video labelled parental advisory explicit lyrics, features daughter Blue Ivy.

Artist Bruno Mars could also be getting in on the act on Sunday. On Instagram Mars published a picture of himself at the Super Bowl venue, Levi’s Stadium, Santa Clara, with the line: “It isn’t a party if Mr $how Up & $how out doesn’t show up…#Confirmed #SB50 #Halftime #Coldplay #Beyonce #TheBrunz”

Beyonce last appeared at the Super Bowl in 2013 and received wide critical acclaim. The halftime show has gained notoriety for its artists, performances and sheer impact in recent years. 2015 saw Katy Perry dancing and singing alongside dancers in shark outfits. 2004 featured the infamous ‘wardrobe malfunction’ of Janet Jackson when she accidentally bared a breast during a duet with Justin Timberlake.