Following a residency at the Acadia Club in Frankfurt, Germany in April, 1965 Ian Gillan joined the group as lead singer. While with Episode Six, Shield recorded six singles for Pye Records, appeared on Ready Steady Go! and toured with Alan Price and Dusty Springfield. In 1966 Episode Six performed at the Casino du Liban in Beirut, Lebanon where he met Greek dancer and singer, Natasha Koumianou. In September 1967, he left the band to pursue a career with her. Later, Glover and Gillan left the band to join Deep Purple.
Koumianou and Shield's cabaret career began in Paris, where they recorded a single, "Honey", written by Shield, for Disques Vogue and continued performing until 1974 at nightclubs throughout Europe, the Middle East and Africa and aboard the ill-fated cruise ship, MS Achille Lauro.
In 1975, Shield moved to Los Angeles, where he wrote and recorded the song "The Way I Feel Tonight". In 1976, he signed with Atlantic Records and his recording of the song was released on the Atco Records label, credited to Shields, in 1977. The recording failed to make an impact commercially, but the song went on to become a worldwide hit for the Bay City Rollers in 1978.
In 1985, Shield's musical Hamelin: A Musical Tale from Rats to Riches written with Richard Jarboe and Matthew Wells, was produced off-Broadway at the Circle in the Square Theatre in Greenwich Village, New York following initial productions at the Olio in Los Angeles and Musical Theater Works in New York.[1]
In 1986, Shield formed The Mighty Echoes, an a cappella doo-wop quartet, which has recorded five albums and continues to perform. They have been seen on stage, film and television in shows such as Who's The Boss?, Murphy Brown, Family Matters, The Suite Life of Zack & Cody and It's Always Sunny In Philadelphia.
In 2019 Shield co-founded the Los Angeles-based Old Man Dinner Band with Pete Thomas.
As a movie actor, Shield serenaded Debra Winger in Wilder Napalm (1993), negotiated with Pamela Anderson in Barb Wire (1996), played a coke-snorting Brit in Crazy Eyes (2012) and acts as messenger for Timothée Chalamet in "Marty Supreme" (2025).
In 2015, Shield was cast as "legendary" rock drummer, Keith Edwards, in the Disney TV series I Didn't Do It.