Just like his brothers Jeff and Mike, Steve Porcaro started out as a drummer under the tutelage of his father Joe Porcaro, before taking up piano. In 1967, his father bought him an organ made by Rheem, a company that specializes in heating and air conditioning. Soon after, he brought his father down to a Guitar Center to trade in the keyboard for a Farfisa with a Leslie 147 and preamp, which Porcaro called his "first real rig". Porcaro's touring career began playing with Gary Wright during his tour in 1977, supporting the latter's The Dream Weaver album. Porcaro and the other original members of Toto then played with Boz Scaggs before forming Toto. Porcaro wrote or co-wrote at least one song on each of Toto's first six albums, with the exception of Isolation. His two older brothers Mike and Jeff were Toto's bassist and drummer as well as session musicians while his father Joe is a prolific session percussionist. Unlike most of his Toto bandmates, he generally did not contribute lead or even backing vocals; he considered himself a weak singer, and sang lead on two of his earlier compositions only because he felt that the vocal styles of his bandmates, with the exception of Joseph Williams, were not appropriate for his songs. The song "Rosanna" was inspired by Porcaro's girlfriend at the time, Rosanna Arquette. He left Toto in 1987 after the Fahrenheit album in order to pursue a more full-time songwriting and composing career. However, Porcaro continued working with Toto in various supporting capacities, assisting with keyboards, drum looping, synthesizers and arranging/composing. Porcaro composed the music for the song "Human Nature" and produced the synthesizer for "The Girl Is Mine" from Michael Jackson's album Thriller, as well as playing synthesizer and keyboard on "Stranger in Moscow" from Jackson's album. Steve Porcaro is currently working on film scores. He composed the music for the FX television showJustified, among many other projects. He collaborated with his daughter Heather Porcaro on her debut album, The Heartstring Symphony, released in 2009. Heather was featured in Paper magazine's "Most Beautiful People" issue in 2002. Porcaro returned to play with Toto at live performances since 2010, when they decided to reform the band and tour in Europe to support Mike Porcaro. They scheduled further concerts in Europe. Porcaro performed on the band's 2015 studio albumToto XIV, co-writing and singing lead on 'The Little Things' and writing/singing lead on the Japan-only bonus cut, "Bend".
Steve Porcaro played a huge variety of synthesizers on Toto albums. While David Paich handled piano duties, it was usually Steve's job to complement the music with creative synth sounds. He was known to use Yamaha GS1, Yamaha DX1, Yamaha DX7, Yamaha CS-80, Roland Jupiter-8, Minimoog, Oberheim Xpander, Polyfusion Modular, Dynacord Add-one and Sequential Circuits Prophet-5 synthesizers among others. The synth solo in the Toto song "Rosanna" is a noted example of his approach. Nowadays he prefers working with software synthesizers. Onstage he is using two Yamaha's, a Montage 8 and a Yamaha Motif XF7 to drive his Apple MainStage-based virtual synth rig, which draws samples from Logic's ES2 plug-in and Spitfire Audio libraries among others.