Lauren Bacall for "To Have and Have Not" (1944), Bacall was so nervous that, to minimize her quivering, she pressed her chin against her chest, faced the camera, and tilted her eyes upward. This effect, which came to be known as "The Look", became another Bacall trademark, along with her sultry voice. Bacall's character in the film used Slim Hawks' nickname "Slim", and Bogart used Howard Hawks' nickname "Steve". The on-set chemistry between the two was immediate according to Bacall. She and Bogart (who was married at the time to Mayo Methot) began a romantic relationship several weeks into shooting. Bacall's role
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.