Lisa-Kainde Diaz, one half of French-Cuban duo Ibeyi, has an inadvisable habit.
Every time she puts music on YouTube, she waits half an hour then checks the comments.
“It’s my little ritual,” she says. “I always look at the first 15, then I stop because, well… you know!”
Recently she uploaded a song called Deathless, whose lyrics tackle police brutality and racism.
Given the sometimes toxic atmosphere of YouTube’s comments section, Lisa-Kainde might have expected to see a stream of hatred. But one message stopped her in her tracks.
“This girl wrote something that really touched me,” she tells the BBC. “‘They buried us, but they didn’t know we were seeds.'”
The quote comes from poet Dinos Christianopoulos, who was sidelined by the Greek literary community in the 1970s because he was gay.
But it could easily be a lyric from Deathless, a cathartic response to Lisa-Kainde’s wrongful arrest, at the age of 16, in Paris.
The performer says she was on the Metro going to a piano class when a policeman started asking her if she drank, smoked or took drugs.
When she replied “no” the officer got “quite rough”, making her remove her shoes and tipping the contents of her schoolbag on the ground.
“It was clearly racist,” says the singer. “The only reason they stopped me was the fact that I had an afro. They thought, ‘Oh, for sure, she’s selling crack.'”
The gendarme only relented when he saw her textbooks and musical scores lying on the ground. “He froze,” she says.
“I think he thought, ‘She might have a little intelligence.’ So he gave me my bag and left.”
Lisa-Kainde says she “buried” the incident for years. “At the end of the day, it was nothing. They didn’t touch me, they didn’t push me, they didn’t try to hurt me that way.”
It was only when stories of police brutality started to crop up with increasing regularity in the news that Ibeyi’s producer, Richard Russell, suggested she address it in her lyrics.
“I remember saying, ‘Why would I write a song about it? My story is nothing compared to what is happening to people every day.’
“Then Naomi said something quite incredible. She said: ‘Lisa, you don’t need to be raped or be killed for it to be wrong. What happened to you was already wrong.'”
Lisa-Kainde decided Deathless should be a rallying cry for people who feel helpless in the face of oppression.
“I was like, ‘Let’s do something!'” she says. “And what we can do, even if it’s small, is write a song for everybody to believe, truly believe, for three minutes that we are beyond death.
“That we are so powerful. That we are large. That there is no end to the power we have together.
“We can make people sing ‘We are deathless’, every night like a mantra. And that’s our little anthem.”
Ibeyi was formed in 2013 by Lisa-Kainde and Naomi Diaz – non-identical twins who say they have almost nothing in common outside music.
“Our mother used to say that if she went to the park and set us down, one would run to the left and the other would run to the right!” laughs Lisa-Kainde, the band’s bubbly and effervescent lead singer.
“We’re complete opposites,” laughs Naomi, the more softly-spoken sister and a spitting image of her father, Cuban conga master Miguel ‘Anga’ Diaz.
“I listen to a lot of hip-hop, and Lisa listens to a lot of jazz. So we can bring what we are, and what we like, into the middle to make Ibeyi.
“We have to go out of our comfort zone.”
The result sounds like nothing you’ve ever heard, fusing the rhythms of Kendrick Lamar with traditional Latin percussion. (Naomi, like her father, plays the cajon and bata.)
The sisters’ harmonies, meanwhile, draw on Nina Simone, Ella Fitzgerald and the rich Yoruba culture imported to Cuba via slave ships from Nigeria and Benin.
“Yoruba songs are quite magical,” says Lisa. “You don’t need to know a lot about Yoruba music to just feel it.
“We were afraid people would feel it wasn’t genuine, but it was inevitable for us because it’s part of our culture. It’s not to be commercial or underground, or cool.”
As soon as Ibeyi recorded their first EP, the band were snapped up by Adele’s record label XL. Owner Richard Russell was so enamoured he offered to produce the band’s first album.
That debut, also called Ibeyi (the Yoruba word for twins), was a meditation on family, love and history, addressing the twins’ late father (Think of You) and also their older sister (Yanira), who died in 2013 from a stroke.
Touring the record forced the band to relive those losses, night after night, for almost two years. So it’s no surprise they were ready for a change on its follow-up, called Ash.
“We wanted people to dance and sing more,” says Lisa-Kainde. “We wanted it to be more physical. As soon as we realised that, our writing changed.”
That’s exemplified on Ash’s ebullient first single Away Away, the carefree video for which sees the duo dance and pull faces in the recording studio.
The slinky Me Voy, meanwhile, is sung entirely in Spanish, to make it “more sensual”.
Yet the band found themselves drawn to more serious subjects too while recording Ash in the midst of last year’s US presidential election.
No Man Is Big Enough For My Arms, for example, samples Michelle Obama’s response to obscene comments Donald Trump was recorded making in 2005 (“the measure of any society is how it treats its women“).
Transmission, meanwhile, quotes Claudia Rankine’s Citizen, a book-length poem about race in America.
“I don’t think we knew we were going to talk that much about what is happening into the world,” says Lisa-Kainde.
“But it was a wonderful surprise to realise we were ready to express ourselves about what we feel is wrong or right.
“We don’t have the truth. We’re not preaching. But we realised we wanted to express it publicly, so it was quite powerful.”
Across the album, Ibeyi also reference painters like Frida Kahlo and Jean-Michel Basquiat, while guest musicians include jazz star Kamasi Washington and Spanish hip-hop artist Mala Rodriguez.
It’s infused with an eyes-wide, everyone-welcome sense of wonder, from a band who admit they’re constantly hungry for new influences.
“It’s funny,” says Lisa-Kainde. “People think that musicians, when they run out of inspiration, should listen to music. I don’t believe in that.
“The day you don’t have inspiration, you should read a book, you should look at Frida Kahlo’s paintings, you should watch a [John] Cassavetes film or just walk around your city looking at architecture.
“There’s so much incredible art that could give you the inspiration back. That’s what will keep you going.”
Ash is released on 29 September by XL Recordings.