Thundercat sits crosslegged and barefoot on a round leather chair, his white Birkenstocks thrown casually to one side. With his zen posture, ornate gold jewellery hanging from his septum and air of insouciance, he brings to mind a buddha. Or at least a buddha with dreadlocks and diamanté-rimmed sunglasses.

The bass player and jazz extraordinaire otherwise known as Stephen Bruner is only 32, yet he already has an impressive musical contacts book, his collaborators ranging from Snoop Dogg and Erykah Badu to Pharrell Williams, Wiz Khalifa and the sultan of yacht-rock, Kenny Loggins. Bruner’s childhood was spent playing in bands with Kamasi Washington, his best friend is Flying Lotus and his time in the studio with Kendrick Lamar, where the pair dived through old jazz records, ended up indelibly shaping the sound of To Pimp A Butterfly.

But it is his third and most successful solo album to date, Drunk, which has brought him to London and the windowless back room of London’s Heaven nightclub, where we meet. Drunk is a wild odyssey of 23 tracks – each less than three minutes long – that fuses Bruner’s untouchable jazz credentials with punk, hip-hop, stoner psychedelia, funk and 80s soft rock, his soulful falsetto voice pondering subjects as varied as anime, losing your wallet and police brutality.

There are many questions I want to ask about the album but what Bruner really wants to talk about is his cat. Tron – or more specifically Turbo Tron Over 9000 Baby Jesus Sally – has long been an inspiration for the bass maestro (Tron Song, which features on his second album, is a loving ode to her) and the time away from her on tour is taking its toll.

“The thing about Tron is she’s a very humanised cat, and is a sweetheart but also very weird, which I enjoy because I’m pretty weird,” he says, reaching for his phone to show me an endless photo stream of Tron in various outfits, including a cat sailor suit. “I treat my cat like she’s my therapist or something, because I talk to her all the time and as she’s gotten older she talks back. It’s pretty funny.”

“Is that a personalised Chanel cat sweater?” I ask, as he pauses over a picture of him and Tron in matching designer sportswear. He nods and laughs, a warm gravelly giggle, like a parent cooing over a newborn.

“She’s a little model cat. I always tell her she’s sexy. I know it’s really awkward because everyone tells me: ‘Stop calling your cat sexy.’ But I’m like: ‘Why would I stop calling Tron sexy? She’s a sexy cat!’”

It’s this endearing weirdness, a lifelong commitment to what he calls the “tradition of not giving a fuck”, that has always fed into Bruner’s music. His dedication to the bass has been obsessive since he was four (his father and brother are also both acclaimed jazz musicians) but is absent of any uptight jazz puritanism, and he has happily lent his talent to every genre under the sun. There was the decade playing bass for legendary thrash band Suicidal Tendencies and then, in the mid-2000s, the time spent on tour in Snoop Dogg’s band. As a session musician at LA’s Silver Lake Studios, he crossed paths with artists from Ty Dolla $ign to Bilal and finally Erykah Badu, who picked him out to join her live band and play on the New Amerykah studio sessions.

But it wasn’t until he met LA rapper and producer Flying Lotus a decade ago that he considered singing, let alone making his own solo records. “From when I was a kid I was always very quiet within myself, I was never attention-hungry,” he says, recalling how he was bullied at school for looking like a girl. “I wouldn’t even tell you I’d play bass, my friends only knew I did because I spent all my time playing. And in the beginning of me becoming a songwriter, I’d get freaked out because it meant talking about things I’d usually keep internal, you know. But that changed the moment that Lotus told me that I should start singing.”

Bruner released his first solo project The Golden Age of Apocalypse in 2011, which positioned him as an artist who could flit between improvised jazz, leftfield electronica and smooth soul within the space of a single song. It was followed by Apocalypse in 2013, and then his more sombre 16-minute long EP, The Beyond/Where the Giants Roam, which was rooted in his grief over the sudden death of his close friend, the piano prodigy Austin Peralta.

Bruner finds it impossible to pinpoint the moment he started creating music for Drunk, though much of it came through working on both Lamar’s To Pimp A Butterfly and Washington’s The Epic. For a long time it was a “weird, twisty-turny selection of songs” that seemed impossible to shape into a single record, until Flying Lotus came up with an idea.

“I remember the day we decided on the name,” he says. “It was funny as hell because the things told in jest are usually the truth, you know, and Lotus was like: ‘This album’s insane, you should just call it drunk.’ And we realised that was exactly the name of the album. The funny thing is the title is what holds it together.”

The record does stumble drunkenly between the laughably silly falsetto of Captain Stupido (“I feel weird/ comb your hair/ brush your teeth”) to serious themes such as heartbreak, sinking into an emotional black hole and the narcissistic perils of social media. Drink Dat, his track with Wiz Khalifa, was simply lifted from a conversation between the pair when they were both going through a tough time in love (Khalifa was about to divorce Amber Rose) and they took to weed and Bombay Sapphire to forget their troubles.

Working with Lamar was a game-changer for Bruner, not only because it landed him his first Grammy, and he speaks about him with almost reverence. “Kendrick helped me to understand how to be very driven and stay focused,” he says. “To this day I wish I was just in the studio with him because the dude is just insane. He’s pretty serious in the studio. You can be joking around but you’ll miss it, because he moves so quick.”

Drunk is not merely lighthearted fare and songs such as The Turn Down grapple with the US’s race problem. Did the highly politicised nature of To Pimp A Butterfly feed into his songwriting?

Bruner fiddles with his wallet and admits, a little dejectedly, that while Black Lives Matter has brought an important conversation to the fore, it has also ensured that every black musician’s output is now discussed in the context of race.

“It’s already too much for me,” he says and shrugs: “Look, the political message of To Pimp A Butterfly didn’t have to filter in. I’m black, so I experience that on a consistent basis. I grew up in LA where these things were always happening, but it’s almost as if people didn’t believe us before. Cops shooting black guys in the back of the head for no reason? That’s not new to me, I grew up knowing that, but it’s not something that I want to guide my path. So I laugh to keep from crying because it’s pretty depressing watching everybody act like a bunch of blithering idiots.

“It doesn’t even feel like racism is real, it just feels like the weirdest ploy, like we’re just being had on so many levels,” he says, laughing loudly again. “It’s even kind of funny when you think about it. A reason not to like someone is ‘because you’re black’. C’mon, man. How dumb is that?”

We conclude that laughter should be utilised more to undermine racism.

“I don’t need to tell myself that I’m black, or that I’m proud of being black, I just am and it just doesn’t matter”, shrugs Bruner, slipping his feet back into his Birkenstocks. “How about that for once?”

Drunk is out on Brainfeeder