Taylor Swift surprises groom and bride

Taylor Swift has become a big part of someone else's love story.

The superstar surprised Max Singer and Kenya Smith in Long Beach Township, New Jersey on Saturday. She sang her hit "Blank Space" at their wedding reception.  

Swift agreed to attend after she received a letter from the groom's sister in April. She wrote how her brother and their ailing mother danced to Swift's song after the newlyweds were married in a hospital room.

The mother passed away shortly after.

Swift also presented the couple with a card that said: "so it's gonna be forever" --- a lyric from "Blank Space."