His other notable roles included Joshua Bolt on Here Come the Brides from 1968 to 1970 and as the lead actor in the 1979 American TV movie Salem's Lot.

[10] While in Mexico, inspired by students who taught him to play the guitar, Soul changed his direction and decided to follow his passion for music.

He traveled with the company to New York City in 1965, appearing in Bertolt Brecht's Baal and John Arden's Serjeant Musgrave's Dance.

[13][14] Soul first gained national attention as the "Covered Man," appearing on The Merv Griffin Show in 1966 and 1967, on which he sang while wearing a mask.

[16] In 1967, he signed a contract with Columbia Pictures[17] and following a number of guest appearances, including the episode "The Apple" from the second season of Star Trek, he landed the role of Joshua Bolt on the television program Here Come the Brides with co-stars Robert Brown, Bobby Sherman, and Bridget Hanley.

Following numerous guest-starring roles on TV, including The Streets of San Francisco, he was cast with Clint Eastwood in the film Magnum Force.

[18] During his career he made guest appearances on Star Trek, I Dream of Jeannie, McMillan & Wife, Cannon, Gunsmoke, All in the Family, and numerous TV movies and mini-series, including Homeward Bound (1980), World War III, and Rage (1980).

[22] Soul also starred with James Mason in the 1979 TV miniseries adaptation of Stephen King's 'Salem's Lot, which was edited and released as a theatrical feature film in some countries.

[34] In the mid-1990s, Soul moved to the United Kingdom, forging a new career on the West End stage, including the role of Chandler Tate in Comic Potential and The Narrator in Blood Brothers.

[27] In August 2008, Soul appeared in the reality TV talent show-themed television series Maestro on BBC Two mentored by Natalia Luis-Bassa.

[44] He appeared with Fred Ward and Willem Dafoe in the film Farewell directed by Christian Carion, which received its U.S. release in 2010.

[45][46] In June 2012, Soul made a one-week appearance with Jerry Hall at the Gaiety Theatre, Dublin, in a reprise of the Pulitzer Prize-nominated play by A. R. Gurney, Love Letters.

[49] In 2014, Soul appeared in a British television commercial for National Express singing "Silver Lady" while driving a coach.

[52] During the years he was filming Starsky & Hutch, Soul had an open relationship with actress Lynne Marta, who died seven days after him.

[2] Soul was ordered to attend therapy classes for alcoholism and anger management after attacking her when she was seven months pregnant with his child.

[61] Although he had stopped smoking ten years prior to his death, he was seriously affected by COPD and had also had a lung removed due to cancer.