Even the press conference at Mona Foma (Mofo) was strange. On Thursday at noon, the festival’s curator and Violent Femmes bassist, Brian Ritchie, spoke to local media as half a dozen helpers waved what looked like CB radio receivers around his face. Ritchie said that one of the themes this year was “primitive electronics” but stopped short of explaining why.

Afterwards, the pack wandered up the hill towards a shipping container, and it became clear that the CB radios were in fact microphones attached to megaphones: a dozen or so megaphones were suspended from the shipping container’s ceiling. Snippets from Ritchie’s conference emitted from them; a vaguely rhythmical, sometimes even pleasant looping. But, as minutes passed, these loops doubled up on themselves, morphing into something squally and nauseating.

The installation was Mick Douglas’ Collective Return, which sat atop the same hill all weekend and derived its loops from microphones embedded in megaphones, carried throughout the festival site by performers, recording and repurposing the conversations and aural ephemera of festival attendees.

Mofo is a major Australian music and arts festival but Douglas’ installation is more indicative of the tone of the weekend than any of the rock or pop bands on its extensive line-up. It’s the most utopian large-scale festival in Australia: there’s no trash on the grass, everyone reuses their stainless steel cups, water is abundant and free and modern art replaces billboards for Vodka brands. The festival attracts a crowd of young and old alike and I didn’t see anyone spew on themselves the entire weekend. You’re in Walsh’s backyard after all. You have to be nice.

Yet the weekend’s most prominent theme imbued the proceedings with a latent sadness. Ritchie’s so-called “primitive electronics”, especially the ubiquitous analogue synthesiser, can’t help but recall a period when these instruments evoked a strange yet exciting vision of the future. Whether dystopian or utopian, glistening or decayed, the analogue synth has become a metaphor for these visions. But, during a period when many are inclined to accept that humankind’s fate is sealed, that climate change is irreversible and its catastrophic effects are inevitable, these sounds don’t evoke dreams of the future so much as they do a nostalgia for having once dreamed of a utopia at all. In that light, they become numbing, melancholic.

The theremin was invented in Russia in 1928 and it’s the quintessence of this bereft mood. At Mofo, thereminist Carolina Eyck’s collaboration with Midnight Oil’s Jim Moginie and Jennifer Marten-Smith happened during light rain. Eyck’s demeanour was bright – the German performer spent a lot of time explaining her strange instrument to the seated audience – but that melancholy still dominated her performance, which included eerie renditions of classical music, including a particularly sinister take on Rachmaninoff’s Vocalise. It was beautiful, forlorn and the highlight of the weekend.

Nearby on the Turrell stage, perched on a lookout above the Derwent River, the noise artist Scott Cotterell took a different tack. Using his mixing desk, his soundscapes were all steel and glass, empires melting, catastrophe and ruination. It was a blunt approach to apocalypse, though it was an objective achieved more effectively by Robin Fox and Byron Scullin’s Melbourne Electronic Sound Studio (Mess) project. An active installation throughout the entire weekend, the locus of Mess was a tower of analogue synthesisers buzzing away in a dining area. At about 5pm each day, the ambience crescendoed in a live performance by the duo, which teetered between industrial techno and harsh noise in a pitch-dark room.

By contrast, on Sunday, the synthesist and songwriter Kaitlyn Aurelia Smith achieved a lightness and optimism with her analogue electronics, which managed to avoid the fetishisation of her tools: they were a means to a songwriterly end.

Not all artists explicitly evoked lost futures – others looked onwards and into the darkness. Circuit des Yeux’s grainy, drone-oriented songs felt enervating in a sunny festival environment, while violinist Veronique Serret’s sparse playing resembled the closing credits to a tragic, filmic finale.

But most explicit was Puscifer’s performance, coming as it did only hours before Donald Trump’s inauguration on Friday night. Comedic and stern in equal measure, the performance started with a stream of ostentatious declarations delivered by an army general via big screen (frontman Maynard Keenan in costume). Drawing mostly from their 2015 album Money Shot, Puscifer’s set combined art rock with professional luchador wrestling. The violent, meaningless spectacle – and the way the band encouraged the audience to roar and cheer it – served to illuminate a point much less accessible in the album itself: humans are capable of kindness but inclined to be violent. Moreover, there is no ideal human; we’re flawed from every angle and doomed to the consequences.

Was Mofo some kind of wine-swilling requiem for humanity? Sometimes it felt that way: listening to music as quiet and ruminative as that of France’s Nadia Ratsimandresy at the height of midday – she specialises in the ondes Martenot, an early electronic instrument that looks like a small keyboard but has a sound similar to and was invented in the same year as the theremin – was about as funereal as festivals get. But there was hope, too. While Los Angeles soul artist Moses Sumney made a point of saying that everything wasn’t going to be alright, his looped and stretched songs nevertheless felt like a refuge from dread. The same held true for Rainbow Chan’s minimal but audacious electropop; so too for Indigenous musician Kev Carmody, who rendered a predominantly white crowd (mostly) silent and listening.

With stunning mountain vistas and not a Dagwood Dog in sight, there’s plenty of reason to smile at Mofo but the line-up seemed structured to pose the more sombre question: what comes next? Do we accept that neither the world, nor our own lives seem likely to unfold the way we hoped they would? How do we change course? It’s a dour subject for a music festival hosted in a rich man’s winery but perhaps it’s what we deserve.

• Guardian Australia was a guest of Mona and Tourism Tasmania

• This article was amended on 24 January to correctly identify Brian Richie’s ongoing role in the band, the Violent Femmes

• This article was amended on 25 January to correctly reflect the technical specifics of Mick Douglas’ Collective Return installation and include a link accordingly