The most prolific of the bunch may be Scarlett Johansson, aka Black Widow, who debuted her music career in 2008 with an album of Tom Waits covers titled Anywhere I Lay My Head. Then, taking a page from fellow actress Zooey Deschanel, paired with an indie singer songwriter and released Break Up with Pete Yorn. The two have recorded a follow up 5-song EP, Apart, due out later this summer.
Idris Elba plays Heimdall in the Avengers and Thor films, but also occasionally moonlights as a DJ. He has released an album inspired by another character he played, John Luther, in the outstanding BBC series Luther, as well as an album inspired by the biopic Mandela: Long Walk to Freedom. And both he and Johansson were featured on The Jungle Book soundtrack from 2016.
All the way back in 2008 Jeff Bridges played the first villain in the MCU, Obadiah Stane, in a little film called Iron Man. He released a self-titled solo album in 2011 which featured an A-list group of performers including famed producer T Bone Burnett, Johnny Cash’s daughter Roseanne, guitarist Marc Ribot, and drummer Jay Bellerose.
The late, great Harry Dean Stanton didn’t play a super hero or a villain in the MCU, but he did appear as a security guard in a memorable cameo in the original Avengers film. Stanton was also a long-time musician (you can catch him playing guitar in one of his last filmed roles in Twin Peaks: The Return) who released an album of folk songs, Partly Fiction, in 2014.
Finally, Iron Man himself, Robert Downey Jr. released an album in 2004 entitled The Futurist. A breezy, standards centric disc, it featured a cover of Charlie Chaplin’s Smile (lyrics by John Turner & Geoffrey Parsons). Downey, of course, also portrayed Chaplin in the 1992 biopic.
But like any MCU film post credits scene, there’s more! Before being replaced by Don Cheadle, Terrence Howard portrayed James Rhodes (War Machine) in the original Iron Man in 2008. Howard released a solo album, Shine Through It, that same year.