First things first: don’t call it a trend. Gender fluidity found its way into more headlines than ever in 2015. But regardless of the moment it’s having in both music and pop culture at large, to dismiss it as a passing fad or, worse, gimmickry is a mistake – one with echoes of that damaging and all too familiar phrase that queerness is “just a phase”.

Proclamations that “gender fluidity is the new black” may be well intentioned, but are unhelpful. Instead, the cultural landscape of the last year has afforded a new openness for artists who don’t identify with gender binaries. Miley Cyrus has been the most visible, declaring in June: “I don’t relate to being boy or girl, and I don’t have to have my partner relate to boy or girl.” She set up the Happy Hippie foundation in aid of homeless and vulnerable LGBTQ young people. In 2014, the indie singer-songwriter St Vincent told Rolling Stone: “I believe in gender fluidity and sexual fluidity. I don’t really identify as anything.” Las Vegas-born rapper and singer Shamir echoed that statement in March, tweeting: “I have no gender, no sexuality and no fucks to give.”

‘I don’t identify as anything’ … St Vincent performing in San Francisco. Photograph: Splash News/Corbis

Around the same time, rapper Angel Haze also came out as agender, and spoke about the way in which their gender identity has evolved. It’s an outlook similar to singer-songwriter Ezra Furman, who explained in July: “I am still exploring what [gender fluidity] means. I’ve not quite decided on a gender identity. I may never decide, and that’s all right with me. I am proud to exist in an ambiguous, undecided state.”

Don’t confuse these statements, however, with pop’s rich history of theatrical, performative gender-blurring. From David Bowie and Prince’s explorations of androgyny and fashion in the 1980s to the role-switching of Ciara and Beyoncé in the 00s, music has been an outlet to expand gender assumptions, to question the socially conditioned roles men and women play – often in brilliant ways. In 2015, artists such as Young Thug, the Atlanta rapper with a penchant for cross-dressing, continued that tradition.

For the current wave of gender-fluid artists, it’s not about dressing up, but about expressing their core identity. Furman muses about gender on the song Wobbly: “I’ve just been changing genders fluidly / Because they’ll never pin me / Down in the pages / Like a bug or bumblebee / Never classify me, don’t try.”

‘They’ll never pin me down’ … Ezra Furman Photograph: Andy Sheppard/Redferns via Getty Images

For many others, however, gender identity is not necessarily central to their music: it’s innate to their being, but largely incidental to their art. Their lyrical focus is on other subjects. Angel Haze’s Back to the Woods is a devastating study of a break-up and subsequent breakdown. Shamir’s album Ratchet is shit-talking party rap straight out of MySpace circa 2005. Amid the lengthy stoned burblings on Cyrus’s surprise Dead Petz release, the most focused and affecting songs are those where she turns her attention to the environment – in particular on 1 Sun, a passionate lament for a dying Earth. That song works well alongside the similarly urgent 4 Degrees, the new propulsive single and scorched-earth vision by transgender musician Anohni – formerly known as Antony Hegarty, an artist who seems to have been casually misgendered by the media for the bulk of her career. Then there’s the transgender deep house producer Terre Thaemlitz, AKA DJ Sprinkles, who has long made gender politics integral to her work. On this year’s brilliant Fresh Insights EP, with Mark Fell, she turned her attention to British class politics and power structures with an extensive sample of a Tony Benn speech. These works may be informed by their creators’ identities – but are not defined by them.

The battle against male/female binaries gained scientific traction last week with the publication of a study by researchers at Tel Aviv University showing that there is no “male” or “female” brain, but instead “multiple ways to be male and female”. These findings, along with the success of artists who identify as gender fluid or anywhere else on the queerness spectrum, are just a small step towards progress in a society so reliant on gender stereotypes that it can seem like propaganda at times. Witness the knee-jerk reaction of the Daily Mail – one of the worst propagators of “men are like this, women are like that” narratives – to the study: “Back in the real world, this simply can’t be true.”

The music world is hardly immune, either: the Lithuanian producer Ten Walls caused outrage with a homophobic rant last June. His comments reflected underlying issues in dance clubs. And in November, the London singer-producer Kindness revealed that homophobic and transphobic abuse from figures feted by the industry made him quit music for several years. Progress may have been made in 2015, but it’s more imperative than ever not to treat it as a fad or selling point.