Last December, Prateek Kuhad was sitting at his family home in New Delhi when his phone lit up with hundreds of messages.
"Have you seen it?" they asked. "This is big."
The song, which hadn't even troubled the US charts, was somehow in Obama's top 35 alongside more well-known tracks by Bruce Springsteen, DaBaby, Lizzo and Beyonce. Kuhad says he has "no idea how cold/mess even reached him", but the endorsement gave his career an enormous boost.
"It was very strange - it just blew up," he says.
First released in 2016, cold/mess defies any cultural assumptions you might have about Indian music. There are no traces of Bollywood or bhangra. Instead, it's a quiet, captivating indie ballad about two lovers whose relationship has hit the rocks, but are too scared to let go of the wreckage.
"I wish I could leave you, my love, but my heart is a mess," sings Kuhad, his voice wavering between hope and hopelessness. "My days they begin with your name, and nights end with your breath."
He started playing it in concert four years ago, and immediately noticed the effect it had on people.
"At a show where nobody had heard the song, I would get a really overwhelming response. So I was like, 'OK, this song's going to be important,'" he says.
Inspired, he constructed a six-track song cycle around cold/mess, for an EP of the same name. "All of the songs were about the same relationship that I was in," he says. "So it starts with a hopeful love song and ends with heartbreak."
'A landmark for India'
Before Obama's intervention, the EP had already been a big hit in India, against many people's expectations.
"There's a big bias in India that to be a successful musician, you have to have songs in Hindi," explains the 30-year-old. "English songs would be like, OK, you could maybe reach a few people in Delhi and Bombay and have a small, dedicated group of fans; but cold/mess really broke that perception."
By the end of last year, Kuhad was playing to an audience of 9,000 at an outdoor concert in Delhi's Garden Of Five Senses, capping off a huge, 30-date tour.
"That was quite a landmark," he says, "because the culture of buying expensive tickets and coming to concerts is not there in India".
The gigs were the culmination of eight years' hard work for Kuhad, whose fame has been building gradually since his first release, Something Wrong, in 2011.
The musician was born and raised in Jaipur and first picked up a guitar at the age of six. "But I gave up after five lessons because it was really hard," he laughs. Later, in high school, he enrolled in a guitar class and promptly failed it.
Nonetheless, he consumed music wherever he could get it. The internet didn't arrive in his area until the end of the 1990s, so his biggest musical education came from one of his sister's friends.
"She lived in Bangalore, which is a much bigger city, and she used to send my sister cassette tapes," he says. "So I heard Savage Garden and The Beautiful South; and the more common pop favourites of the time like Backstreet Boys and Boyzone; and also a lot of classic rock like Pink Floyd and Nirvana."
In 2008, he enrolled in NYU's College of Arts and Science, taking a joint degree in maths and economics, with a view to becoming a consultant or working in finance.
But living in America, he was introduced to the music of singer-songwriters like Elliot Smith, Laura Marling and Nick Drake - and something clicked. He started to play the guitar more earnestly, writing his own songs and picking up gigs around the city.
Even then, he says, "music was never supposed to be a career choice or something I would do seriously". He took a job in consulting but, after a few months, started to suspect corporate life was not for him.
"Nothing was working out and I was really doubting myself," he says. That uncertainty poured into a song - "There's something wrong with the way I think" - that became his first single after he quit his job and moved back to New Delhi.
Released independently, Something Wrong put him on the map - but the singer can't bear to listen to it now.
"I'm quite embarrassed of that whole record," he laughs. "I find it to be sloppy songwriting and really mediocre production."
He prefers to think of his next release, 2013's Raat Raazi, as his "first serious release". Sung in Hindi, it highlights his finger-picked guitar style and intimate, boy-next-door vocals.
But it was advice from music industry legend Jeff Bhasker that really helped him hone his writing. The producer - who has worked with Kanye West, Taylor Swift, Rihanna and Madonna - heard Kuhad's music while delivering a masterclass in India, and told him he needed more "melodic movement" in his songs.
"That really got me thinking," says the singer, "because I never really put a lot of effort into melodies.
"Like, I'm consciously thinking about the words - deleting and reworking and keeping a track of them - but with melody I'm more instinctive, I don't think about it too much.
"So now I've reached more of a middle ground. Sometimes I let the melody flow, but other times I'll take a step back and judge it, which is not something I did before. So I found that feedback quite helpful, quite insightful."
You can hear the impact of that advice on the cold/mess EP. The rise and fall of his melodies tell stories of love, angst and conflict, even if you aren't paying attention to evocative lyrics like: "We grow old with these folds of time / Mould each other into perfect wine".
Released in 2018, the EP debuted at number one in India, and Kuhad became one of the country's most-streamed artists when Spotify launched there last year.
The title track's popularity only increased when Kuhad released a cinematic video, starring actors Jim Sarbh and Zoya Hussain, that captures the raw, emotional ups and downs of a relationship.
Like the song itself, it challenged the status quo of India's music industry.
"Most music videos you see in Bollywood, they're just more dramatic," says Kuhad. "There's a lot of colour and big sets and everything is loud. But cold/mess ended up being completely different. The characters were super-real, nobody was dressed weirdly, the shots felt like real life in Bombay.
"The moment it came out, there was a huge response in my live shows."
But while the EP made Kuhad a household name in his home country, there was a sense of frustration that it didn't travel more widely.
"A lot of us felt that cold/mess didn't get its due, especially internationally," he says, which is why the singer-songwriter has signed a deal with US label Elektra Records to re-release the EP this winter. "To lay the groundwork for the next album that's coming out."
Work has already begun on that record. Kuhad, who speaks to the BBC from the home studio where he records all his demos, has "shortlisted 20 or 30 songs" (and an equal number of album titles) in preparation for a full-length project next year.
In the meantime, he's already had another viral hit in India with Kasoor, a sweet, romantic ballad, whose video was streamed eight million times in just 24 hours.
The clip sees dozens of Kuhad's fans reading and reacting to a series of statements - "Think about your first love" or "Think of someone you're missing right now" - while filming themselves on their phones.
It feels like a prototypical lockdown video, but the singer says it was planned and conceived almost a year ago.
"So many people have done crowd-sourcing videos," he says, "but Kasoor really shone because there was a lot of attention to detail.
"About 500 people sent in reaction videos, and my director went through every single one of them, finding every emotion in every single frame. It was a maniacal editing job."
The laughter and tears perfectly complement the delicate humanity of the song - which feels like another calling card for Kuhad's burgeoning international career. But does he have a favourite?
"Yes!" he smiles. "My favourite is this one where there's a couple and the question is, 'When was your last kiss?' and the couple just kisses right there. That's super-cute."
The cold/mess EP is out now.