The song was written by David Paich, who has said that the song is based on numerous girls he had known. As a joke, the band members initially played along with the common assumption that the song was based on Rosanna Arquette, who was dating Toto keyboard player Steve Porcaro at the time and coincidentally had the same name.
The video (directed by Steve Barron) is set in a stylized urban streetscape, with Rosanna shown as a dancer whose bright red dress contrasts with her grey surroundings. The band plays within a chain-link fence enclosure. Cynthia Rhodes is featured as the lead dancer, which led to her being cast in Staying Alive the following year. It also featured Thomas Guzman-Sanchez of the dance group Chain Reaction as one of the male dancers. He did the Boogaloo/Popping body wave leaping over another dancer. New bassist Mike Porcaro appears in this video, as original Toto bass player David Hungate left before the video was made. A young Patrick Swayze can be seen as one of the dancers.
David Paich – synthesizer, piano, backing vocal, horn arrangements
The Slovenian a cappella group and jazz choir Perpetuum Jazzile performed an a cappella version of the song at their Vokal Xtravaganzza concert in Ljubljana, Slovenia on November 9, 2010, a video of which was uploaded to YouTube on December 30, 2010.
^Whitburn, Joel (2004). The Billboard Book of Top 40 Hits, 8th Edition (Billboard Publications)