One of Grace Cummings’ earliest memories is going into the lounge room to tell her parents about the night terror she’d had. The four-year-old was tormented by the possibility of what happens after death, her imagination stretching the possibilities into grim eternities. When she padded into the lounge room to tell her parents, she saw exhaustion shadow their faces. So when they asked what was wrong, she lied: “Witches.”

“I thought, what would a child say?” she tells Guardian Australia.

This memory informed her track WITCH! WITCH! WITCH! on her new fourth album, Bloodhorse!, which deals in themes of identity, gaslighting, manipulation and betrayal, with a depth that only someone well-versed in otherworldly angst could reach. The astonishing fervor of her music has drawn comparisons to that of Nico, John Cale, Marlon Williams and Nina Simone. The Guardian has previously described Cummings’ voice as both appearing “to spring from a deep well connecting her diaphragm to the massive tectonic plates below” and “powerful enough to pound granite into dust”.

Recorded in Topanga with producer Jonathan Wilson (who has also worked with Angel Olsen and Father John Misty), Bloodhorse! is named after the kind of thoroughbred that is a nervous wreck by temperament.

“I really find it hard to quieten down,” Cummings says. “I grew up thinking that there was something wrong with me, or I was difficult, or too sensitive, or too much. The peace that I found in music is a legitimate lifesaver.”

Since releasing her debut album, Refuge Cove, in 2019, Cummings has had success both in Australia and overseas, playing international festivals including Great Escape in the UK. Though she is a sure-footed songwriter whose last album, Ramona, was shortlisted for the 2024 Australian Music prize, Cummings has spent a lifetime trying to better fit people’s expectations – ever since that formative night-terrors incident.

In her track The Magnum Opus of The North is a Cowboy Boot, she describes the kind of man “who cosplays as tortured poets or cowboys, pretending to be disaffected”. Recently she’s come to the realisation that she has been a bowerbird in her relationships, borrowing opinions, taste and values and assuming them to be her own.

“I’ve been mirroring people’s behaviour in order to please them,” she says. “I’m autistic and I didn’t really realise what that meant. Now I want to live my life the way that I am – in a way that I would probably be burned at the stake for a couple of hundred years ago. I only want to do things that teach me something, or help somebody. The fucking coolest thing is to care. And I do care, so much.”

The aforementioned cowboy theme pops up a few times, including in an abbreviated, highly sexual AI country banger with a male vocal (it’s as surreal as it sounds), and in the video for My God, shot at The Lawrence Rodeo in Maclean, New South Wales. The rodeo becomes a physical manifestation of the hatred she describes in the song, the kind of hatred that people direct at strangers online. “The rodeo is this fucking strange environment where people have a bloodlust,” Cummings says. “A real depiction of us just sitting and watching something that’s quite awful.”

My God, the first single from the album, has a percussive urgency with its uh-huh-huh refrain. When recording it, Cummings had pneumonia, which forced her to experiment with her breath – picture the sound you might make when jumping into freezing water. “I’m leaning more into vocalisation without words, and this was primal sounding,” she says. “It’s the way that some people soothe themselves and their nervous system.”

With her track FAKE, she wants the listener to feel as though they are being dragged under water. The line “if you would just be a good girl” is so offensive to her that she has omitted it from the official lyrics and uses a glottal stop to make it almost unintelligible. In the video, she chokes on viscous black blood when singing it.

Seeing Cummings live, there’s a similar feeling of purging, as if watching a seance or someone speaking in tongues. “There’s definitely a milking of catharsis going on, but there’s no acting in it,” she says. “Sometimes I have no idea what’s going to happen and my band are like, fuck. But then you’re like, ‘Oh well, I guess that was there and needed to come out at some point’.”

In the coming months, Cummings and her band – Miles Brown, Louis King, Tex Keane-Cullen and Tommy Brooks – will tour Australia, the US and Europe. Cummings has never paid herself a wage as a musician and works as a disability care worker (“which I love”), so it goes without saying that she thinks the arts are undervalued in Australia and undervalued as an export. “My managers are the most incredible, generous people ever, but a lot of the music industry is about finding people on the spectrum that’ll do it for nothing – because we can’t not, you know?”

While she’s determined, after a few years of “incredible pain and change”, to not seek out external validation, I can’t resist telling her about some of the comments I’ve seen on YouTube under the My God video, like: “Hearing Grace live this year is going to be the highlight of my youth.”

“That makes me extremely grateful and glad,” she says, “but a little inside of me goes, ‘Imagine if you knew me though.’ I still have that little dig at myself.”

• Bloodhorse! is released on 14 August

Grace Cummings’ songs to live by

Each month we ask our headline act to share the songs that have accompanied them through love, life, lust and death.

What is the last song you sang in the shower?

Mary Don’t You Weep, as performed live by Aretha Franklin on Amazing Grace.

What is the song you have listened to the most times this year?

Melody by Serge Gainsbourg.

If your life was a movie, what would the opening credits song be?

About 10 completely different songs playing very loud over the top of each other.

What is your go-to karaoke song?

Crying by Roy Orbison.

What underrated song deserves classic status?

Life Line by Harry Nilsson.

What is a song you loved as a teenager?

The Tourist by Radiohead.

What is the first song/album you bought?

The White Stripes by the White Stripes

What song do you want played at your funeral?

The End by the Beatles.

What’s one song you wish you didn’t write?

I wanna change something on every song I’ve ever written! But that’s how it goes. I think sitting with decisions you’ve made in the past are just a part of life.