Festival shuttles often make for excellent people watching, and none more so than the ride between Sónar By Day and Sónar By Night, where tipsy partygoers cram onto a repurposed public bus to decompress between the long day gone and the longer night ahead. While one woman took a crucial power nap, strangers from Serbia, Italy, Spain and the US engaged in lineup chit-chat and deeper conversations on their respective nations. "I hate the US," said the American girl, who was rolling solo on one hour's sleep. It was her first time in Europe, and she was here specifically to see Aphex Twin and Peggy Gou. "Nobody wanted to come, so I was like, 'fuck it I'm going.'"

For 30 years, Sónar has inspired this kind of dedication from electronic music fans all over the world. The Barcelona festival launched in 1994, at a time when the local authorities were keen to exploit the momentum of the 1992 Olympics by supporting cultural projects. Three friends—Enric Palau (music), Ricard Robles (film) and Sergio Caballero (art)—wanted to unite their passions under a single banner and, in the case of electronic music, elevate its reputation and cultural status. This is why they created the day and night programmes and placed such an emphasis on technology, innovation and education. From day one, Sónar was more than just a rave.

Rosa Bellsolà was in the 6,000-strong crowd in 1994. Now in her early 50s, she's only missed a handful of editions since, taking in memorable performances from the likes of Grace Jones, Roxy Music and Björk. She, like thousands of electronic music fans from Barcelona and across Spain, has grown up with Sónar—it's shaped her taste in music, forged friendships and created countless special moments. Without it, electronic music in Spain—and probably Europe—would look very different.

"I first went when I was 21 or 22 as a raver," she said. "I've been with my four previous partners—my group of girls has stayed the same, only the boyfriends change—and in 1996, I helped design the cover for the first or second CD. It's been a real personal evolution."

Shygirl and DJ Marky performing at the SonarLab by Resident Advisor stage.

Grime artist and founder of influential label Butterz Elijah bringing his Yellow Squares to Sonar+D.

The provocative reggaetonera Bad Gyal.

So how does a festival of Sónar's ambition celebrate 30 years? By going all out. The programme—which several people said felt like the best in ages—was overflowing with huge names, intriguing collaborations, premieres, talks, AI films and plenty more besides. It was especially heartening to see so many Spanish acts in the spotlight. These shows were devoured by large audiences of teens and 20-somethings living their best lives, which says a lot about Sónar's impressive staying power.

"We've been planning the 30th edition for a bit longer than the usual 12-month period," said cofounder and co-director Enric Palau. "We didn't want to be nostalgic and thought the best way to celebrate was to do what we always try and do: exhibit the best of the present and immediate future of music. Quite a lot of artists played for the first time. We really tried to be representative—for example, by showcasing this current hybridisation of Latin music, electronica and queer scenes."

My personal highlight was the provocative reggaetonera Bad Gyal, part of a crop of new Spanish stars raised on trap, reggaeton and dancehall. This is a thorny issue—reggaeton and dancehall are both born from former colonies in the Caribbean—and accusations of appropriation have trailed behind these artists' success. At the same time, they've received huge support across Latin America.

This was Bad Gyal's first time at Sónar By Night. Against a backdrop of blinging pinks and purples, she twerked and strutted around the stage with commanding presence. What she lacked in vocal prowess—the backing tracks did a lot of the heavy lifting—she delivered in swagger, catchy hooks and the occasional Sean Paul or Destiny's Child interlude. Her young, queer and Spanish audience met her every move with squeals of delight. One group, all bucket hats and wraparound shades, sang and gestured to each other, stars of their own music video. There were no phones in the air—everyone was dancing too hard.

To acknowledge Sónar's overwhelming contribution to our scene, we asked seven fans from different fields to share their favourite memories.

Angel Molina

A fixture since the beginning, the Spanish techno DJ has seen it all at Sónar.

I've got so many memories imprinted in my mind—it's difficult to pick one. On a professional level, without a doubt it has to be my first appearance as a DJ in 1994. I remember being so nervous. Playing Sónar was my first major milestone as an artist. I played a dizzying, risk-taking set that ended with a minute of pure noise followed by total silence. The silence was broken by applause from the crowd. It's impossible to describe that feeling.

As a raver, I'd say probably X-102 Discovers The Rings Of Saturn's performance in 2008, if only for its historic musical value and how unusual it was to see Mike Banks and Jeff Mills sharing a stage.

On a personal level, it has to be when I met Duran Duran, a band I'd been following as religiously as any other since the '80s. My aim was simply to say hello, but I ended up swapping stories and chatting with them (particularly Nick Rhodes) for about an hour in their dressing room—a pretty rare moment.

Rosa Bellsolà

There in 1994 and still a fan, this local raver has grown up with Sónar.

The first edition of Sónar By Night took place by the beach in the Pavelló de la Mar Bella. I remember the whole place shaking to the sounds of Plastikman as everyone bounced and sweated in the stands. I think that same year we went to an off Sónar party in a pitch-black basement where Miss Kittin played with no top on.

A few years later, around the end of the '90s, the crowd started to change and people began coming from abroad. By then the party went non-stop from Thursday to Sunday—and even beyond. We'd meet foreigners on the dance floor, strike up little friendships and tell them which afterparties to go to. Some of them even turned up at a house party once!

Luis Costa

How two dance music titans stole the Spanish writer's heart.

At the 1997 edition, I stood in the first row to watch Daft Punk present their Homework album live. I was crazy excited to see them, and they duly delivered a spellbinding performance. I remember standing there while An Der Beat did the warm-up and hearing some lads next to me say, "Wow, Daft Punk are great, right?" I couldn't stop laughing.

At the next edition, I was eagerly anxious to see the masters, Kraftwerk. Arriving barely a minute late to the performance, I remember hearing their first noises as I approached the entrance. Even from outside the sound was really good. After their extraordinary concert, I thought to myself, "they're the ultimate legends and I bloody love them. Respect." It was a genuine epiphany.

Mary Anne Hobbs

The UK DJ and BBC Radio 6 Music broadcaster reflects on a game-changing night for dance music.

The first Sónar showcase I hosted in 2007 remains one of the greatest nights of my life. For the very first time, we took dubstep out of South London and onto a European festival stage ten times the capacity of DMZ at Mass in Brixton. We had no idea if anyone would show up, but on the stroke of midnight, rivers of bodies began flooding into the arena to see Skream, Kode9 & The Spaceape, Oris Jay and I play. The next day every headline in the European press read "DUBSTEP TAKES SÓNAR." The night was ecstatic, and it changed the trajectory of electronic music for all time.

Daito Manabe

One of Sónar's most frequent guests remembers a special performance.

I make a point of hitting up Sónar nearly every year, whether I'm there to perform or just to enjoy the show. One of the biggest draws is getting the chance to hang out with all sorts of artists. The sheer variety of experiences on offer from dawn till dusk is mind-blowingly thrilling. One memory that really sticks with me is the performance by Ryuichi Sakamoto and Alva Noto. Sure, I've seen them do their thing before, but their finale in 2018 was beyond mesmerising. The blend of Teatre Grec's architecture, the pulse of nature around it, Ryuichi's piano and Alva Noto's beats all came together to form a truly awe-inspiring spectacle. That image, that moment—it's seared into my heart forever.

Martje Kremers

The agent for Justice and the Ed Banger crew has been working with Sónar for more than two decades.

I have many memories from the last 23 editions—I don't think I've missed a year since 2000! I've had artists performing at the festival almost every year, and have always been very grateful for this. The Sónar team are so friendly and easy to work with. My clearest memories are probably all the amazing live shows we did, like Justice in 2008 and again in 2017, SebastiAn, Jackson and his Computer Band, Boys Noize and Louisahhh. I also remember standing on stage with the Sónar owners and Boys Noize, Brodinski and a load of other people watching Chic performing "Good Times." They sure were good times!

Or there was the Ed Banger House Party in 2016, when Pedro Winter unexpectedly opening his set with Justice's new comeback single, "Safe And Sound." No one had ever heard it before—the audience lost it. They played the most amazing set under the glare of a full moon. We were all dancing and happy. Later that year, the track was released, followed by their third studio album, Woman. Justice then played their Woman Worldwide live show at Sónar By Night the following year, which was incredible. Ed Banger has always had a strong connection with the festival. We love Sónar.

Eloisa Blitzer

The MARICAS cofounder chooses a live show in the heat of Sónar By Day.

Sónar has always been my favourite festival in Barcelona. Music- and crowd-wise, it's everything I could ever dream about. I'll never forget last year when SIMONA (one of my favourite artists at the moment) made her debut at Sónar by Day at around 4 PM. There was this crew of really cute people singing her songs in the 30-degree June heat. It was her first time presenting her EP live with her whole band, which made the whole thing feel extra special. Seeing her perform and play her amazing music while surrounded by all our friends and family was honestly a dream come true. It was a moment I'll treasure forever.