Michael Kiwanuka wrote this epic 10-minute track with American musician and hip-hop producer Inflo. Kiwanuka told Mojo: "'Cold Little Heart' probably most describes where I got to after getting stuck in my own writing. Usually I write songs in my room on acoustic guitar. But working with 'Flo, I needed to try different ways to shake things up. Cold Little Heart was the result."
Kiwanuka's vocals only kick in after a five-minute guitar-led instrumental. He said: "I've always liked soul music from the '70s like Isaac Hayes and Funkadelic. A lot of it is really patient - 'Maggot Brain' slowly evolves, 'Walk On By' slowly builds. They're like suites, but it's hard to come up with that with just acoustic guitar. (Writing) in the studio at the same time as recording you've got keyboards, guitars, effects, electric guitars, so you can really go to town with long structures and passages."
The song is the opening track of Love & Hate. Co-producer Danger Mouse told Mojo:
"The moment we finished 'Cold Little Heart,' there was no way it wasn't going to open the album. Everybody knows about Michael's voice, but he's also an amazing guitar player and songwriter. I said, 'The first song you release off this album should be an instrumental.' We didn't do that,
This is the next best thing; opening it with a song, where he doesn't sing in the first five minutes, but it's still all Michael, his melodies and his beautiful guitar playing."
A shortened version of the song soundtracks the opening credits of the 2017 HBO miniseries Big Little Lies, starring Nicole Kidman and Reese Witherspoon. When Kiwanuka agreed to let the series use the song, he thought it would be background music in one of the scenes; he was shocked to learn that 90 seconds of it play over the opening credits in every episode, forming the musical theme for the entire series.
The show was a hit, granting new life to the song, which got relatively little radio play because it's very long and doesn't fit a specific format. It got even better when Big Little Lies won eight Emmy Awards, including Outstanding Music Supervision. "Cold Little Heart" played every time the show won an award at the ceremony.