In his visor-and-face-mask combo, Daveed Diggs resembles a cross between a welder and a highwayman. He peers into his webcam as he walks, offers a “Yo!”, and finds a quiet corner of a Los Angeles studio to sit down, then whips off his headgear to reveal spidery braids and a black beard. An East Bay T-shirt serves as a reminder that the 38-year-old hails from Oakland, the Bay Area city that provided the backdrop, and the dazed deadpan sensibility, for Blindspotting. That extraordinary film, released in 2018, which Diggs co-wrote and starred in, twisted straight-arrow subjects (racist police violence, unconscious bias, gentrification) into comic vignettes without any loss of gravitas.

He is speaking today from the set of the TV spin-off series. “It’s the same idea as the film,” he says. “It’s a comedy in a world that won’t let it be one.” Praising Blindspotting in these pages two years ago, Mike McCahill described it as “2018: The Movie”, but there seems regrettably little chance that the series will look dated by the time it reaches our screens. “The topic of the different policing of poor and brown people is not new to the current resurgence of Black Lives Matter,” Diggs says. “That’s the world we live in. It’s as consistent as it has always been.”

Audiences have had no shortage of Diggs this year. At the start of the pandemic, Disney+ streamed a 2016 recording of the Broadway musical Hamilton, originally intended to be released in cinemas next year, which features the actor’s swaggering, Tony-winning dual performance as Thomas Jefferson and the Marquis de Lafayette. Diggs is also the star of Snowpiercer, the Netflix series based on Bong Joon-ho’s post-apocalyptic train-bound thriller (a second season is in the can, with a third shooting next year). He recently played a comically carnal Frederick Douglass in the irreverent abolitionist drama The Good Lord Bird, and next year he will be Sebastian the Crab in the live-action remake of The Little Mermaid. “I enjoy so much,” he says when I mention this eclecticism. “There’s really not a lot that I hate doing. My taste in everything is always the thing I haven’t tried before.”

This month, he pops up in Soul, Pixar’s animated fantasy about a music teacher scrambling to get back to Earth from the afterlife. Diggs’s vocal imprint is minor – he has one scene as a barbershop know-it-all – but his main contribution was as part of a group of “cultural consultants”, also including the musicians Quincy Jones and Questlove.

“It’s Pixar’s first film with a black protagonist,” he says, “so they wanted feedback on cultural relevancy from a ton of black folks. They’d show us character designs and ask: ‘Does this feel like a person you know?’ or ‘Are you offended by this in any way?’ One person said, ‘In the background voices, I didn’t hear anyone who wasn’t speaking English, and that’s not my experience of New York.’ I thought that was such a brilliant note! It hadn’t occurred to me. It’s buried in the mix – but somebody picked up on it.”

He also sat in on feedback sessions, where material was mercilessly torn apart. “I don’t think I could write for Pixar,” he laughs. “They’ll hack away at a thing if it’s not working. It’s brutal. Nobody is concerned with anyone’s feelings, they just want to make a great film. I was a newcomer, so to me it sounded like they were killing babies all over the place.”

The actor and writer Rashida Jones – Quincy’s daughter, who co-wrote Toy Story 4 – has called Pixar a place where “women and people of colour do not have an equal creative voice”. Diggs believes the studio is trying to remedy that. “It’s part of an industry-wide self-examination. Everybody means well, but there’s so much unconscious bias happening. If you don’t have representation in the upper ranks – if there’s no producer of colour at the top, and no upper-level writers of colour – then it doesn’t matter what’s happening in your writers’ room. When younger writers of colour present interesting ideas, those always get cut because there’s no one at the end of the line who understands the cultural relevance and specificity of those details. No one’s actually saying: ‘We don’t care if black folks or queer people manage to see themselves in this.’ But that’s the result. You don’t know what you don’t know.”

It is a lesson he has taken with him into the Blindspotting series. “Our writers’ room was almost entirely women because we are writing for a female protagonist, and we were aware we would miss certain things because of our own blind spots. We also work with as many female directors as we can to check us on those things all the time.”

Diggs is an eloquent speaker – check out his 20-minute commencement address at Brown, his alma mater, for definitive proof – with a gift for juggling light and dark subjects. This month, for instance, his avant garde rap trio, Clipping, released a bouncy tween-pop single, Puppy for Hanukkah, and a sinister, horror-soaked new album, Visions of Bodies Being Burned. Typical tracks include Pain Everyday, where the descendants of white racists are haunted by the ghosts of lynching victims, and Body on a Pile, which surveys the carnage following the slaughter of several cops.

Among their previous songs is The Deep, which imagines the babies of drowned pregnant slaves building an underwater world. Why is horror – from Get Out and The People Under the Stairs to this year’s Lovecraft Country and His House – so adept at conveying black experience and black history?

“The great thing about horror as a genre is that the times generally identify what the monster is,” he says. “When you look at Jordan Peele’s work, or any of the stuff enjoying popularity right now, it allows black creators to shine a spotlight on the things that have always been monstrous, and then to make physical monsters out of them. They become visually frightening so everybody gets to be scared of them.”

Absent from the new album is the single Chapter 319, released on Juneteenth this year as a response to the murder of George Floyd. Diggs, a famously dexterous rapper, puts it as bluntly as possible on the track: “Donald Trump is a white supremacist, full stop/ If you vote for him again, you’re a white supremacist, full stop.” The song was written in a day, he tells me, “to be played at protests”; it also breaks one of the band’s self-imposed rules by having Diggs rapping in the first person. “Most rap is rigorously first person, but we always wanted to be able to talk about things without having people assume we were living them.”

Much of Clipping’s music, like Pixar’s films, has a timelessness that will allow it to be understood easily in decades to come, whereas Chapter 319 may need footnotes for listeners in 2040. “That’d be great if it did,” Diggs says, smiling sadly. “It’d be really nice if we didn’t all immediately understand what that song was about.” I was planning to end by asking about his hopes for America in the coming years. But I think he just answered that.

• Soul is streaming on Disney+ from 25 December.