In 2015, Heap signed a worldwide agreement with Downtown Music Publishing. The deal covered Heap's portion of Taylor Swift's fifth studio album "1989" finale, "Clean," plus five songs from Heap's 2014 album, "Sparks": "The Beast", "Entanglement", "Climb to Sakteng", "Run-Time", and "Cycle Song". Her participation in "1989" led her to become part of the production team that won Album of the Year at the 58th Grammy Awards. She was one of the artists featured in an episode of the 2016 PBS docuseries "Soundbreaking", and she narrated and composed music for the 2016 documentary "Crossing Bhutan", which premiered at the Santa Barbara International Film Festival. Also in 2016, she was commissioned by French advertising agency BETC and British company Cow &amp; Gate, in collaboration with researchers from Goldsmiths, University of London, to help write a song which would be proven to "make babies happy", which was eventually titled "The Happy Song". The track was engineered through several months of scientific testing and was released in October 2016.