David Paich, Steve Lukather and the Porcaro brothers (Jeff, Steve and Mike) were session musicians whose credits included Steely Dan, Boz Scaggs, Michael Jackson, Cheap Trick, Peter Frampton and The BeeGees. In 1977, Paich and Jeff Porcaro started to talk about forming their own band, and in short order they put a group together. Supposedly, they wrote Toto on their initial recordings to differentiate themselves from the other bands in the studio and the name eventually stuck.
While Toto's first album was successful, the next two LPs were commercial disappointments. The band's fluid style migrated between pop and arena rock due to the competence and diverse styles of the members, but this was not a recipe for broad commercial success. Toto responded with Toto IV, a crafted pop album that reached #4 and went triple platinum in 1982.
Unfortunately, the band's next album, 1984's Isolation, returned to the arena rock style and did not resonate with their audience (who were expecting more songs like "Rosanna" and "Africa"). Part of the change may have been influenced by a change in vocals, as lead singer Bobby Kimball left the band and was replaced by Dennis "Fergie" Frederiksen.
Ironically, the one hit off Isolation was a song that could have fit in on Toto IV -- "Stranger in Town." This is underscored by David Paich's vocals (he also sang lead on "Africa.") The song was inspired by the 1961 British film Whistle Down the Wind, about a group of schoolchildren who discover an escaped convict and mistake him for ... well, watch the video; you'll see. Helped by some airplay on MTV, the song reached #30 on the charts (one of 9 top 40 hits for the band).
Although the band's popularity faded after the late 1980's, they have more or less remained together to the present day, with some personnel changes (sadly, Jeff Porcaro died in 1992).
Cool trivia fact: "Stranger in Town" was directed by Steve Barron, who also directed Michael Jackson's "Billie Jean, A-Ha's "Take on Me" and Dire Straits' "Money for Nothing" and many, many other 1980's videos.