Lauren Bacall in the script was originally much smaller, but during filming, her part was revised multiple times to extend it into the lead part that it became in the released film. Once released, "To Have and Have Not" catapulted Bacall into instant stardom, and her performance became the cornerstone of her star image, the impact of which extended into popular culture at large, even influencing fashion, as well as film-makers and other actors. Warner Bros. launched an extensive marketing campaign to promote the picture and to establish Bacall as a movie star. As part of the public relations push, Bacall made
What Love Is Made Of three minutes and fifty-five seconds (3:55), "What Love Is Made Of" is an uptempo dance and house track that has been described as "rave-y" and "trance-y". Its instrumentation contains the sounds of pianos and synthesizers. Jordan Sargent of "Spin" observed that it continued the musical style first introduced in Katy's 2012 extended play (EP), "Danger EP", which was "straight-forward house". Idolator's Sam Lansky compared her performance in the song to recording artist Siobhán Donaghy. Critical response to "What Love Is Made Of" was generally positive: most critics noted Katy's vocal performance and commended its sound. Siân Rowe from "NME" was