Banks attended Charterhouse School in the mid-1960s, where he met fellow student Peter Gabriel in 1965. Together with drummer Chris Stewart they formed a band called The Garden Wall. This band merged with another called Anon, which included Rutherford and Anthony Phillips, and they recorded a set of demos which ultimately led to the formation of the band that became Genesis.
In its early progressive years, Banks' songwriting heavily influenced Genesis' musical direction, and his elaborate keyboard solos — such as the piano intro to "Firth of Fifth" and the instrumental section of "The Cinema Show" — were one of the hallmarks that established the band's larger-than-life sound. Notable Banks-penned songs from Genesis' repertoire include "A Trick of the Tail," "One for the Vine," and the anthemic ballad "Afterglow," which remained a popular live song for years.
After Gabriel's and Steve Hackett's departures from Genesis, Banks was the first member of the group to release a solo album. But unlike bandmates Rutherford and Phil Collins, who saw great solo success, Banks' solo efforts usually sold only to a core audience of Genesis' devotees. He seemed unable to break out into mainstream success, as if he needed the framework of Genesis to make the public receptive to his songs.
Despite this, he remains one of rock's most respected — by critics and peers — songwriters and instrumentalists.
Banks has also created some film scores. He wrote the soundtrack to Quicksilver, starring Kevin Bacon, but was fired from the film 2010 by director Peter Hyams. After Genesis dissolved, Banks created some elaborate orchestral pieces, which he began recording in 2002.
In 1998, some fans pulled together a tribute band called Strictly Banks, and performed a set of Banks' solo songs, marking the first time most had been performed before a live audience.