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 dance music. She then got a bassline which made her "want to dance", and included it in the track. She also told the website that she wrote the song about the "feeling of love, what one person can give to you that someone else can't". What Love Is Made Of" was premiered during Irish DJ Annie Mac's eponymous program on BBC Radio 1, on 10 May 2013, though its digital download only occurred on 5 July 2013. It was serviced as an extended play, where it was bundled with three remixes, by MK (Mark Kinchen), Felix da Housecat and Brackles.