Sound Waves and Side Projects: The Story of Stereo, Finland’s Electronic Alter Ego

When major mainstream bands hit the brakes for a much-needed hiatus, fans often wonder what the members will do with their sudden freedom. Will they launch quiet solo acoustic projects? Retreat from the spotlight entirely? For Leo Hakanen and Jere Marttila—the master guitarists and primary songwriters behind Haloo Helsinki!, one of Finland’s most successful pop-rock behemoths—the answer was entirely unexpected.

Instead of dialing down, they turned the volume up, shifted genres, and stepped out from behind their guitar rigs to form Stereo (stylized as STEREO), a dynamic Finnish electronic dance music (EDM) and pop-producer duo.

The Genesis of Stereo: A Creative Outlet

During Haloo Helsinki!’s planned break from the spotlight in 2018–2019, Hakanen and Marttila found themselves with creative energy to burn. Rather than resting on their laurels, they decided to explore a completely different sonic landscape. Transitioning from stadium-ready alternative rock anthems to sleek, modern electronic production, the duo created Stereo as a vehicle to experiment with club beats, atmospheric synths, and collaborative pop songwriting.

While they remained the primary masterminds—handling production, songwriting, and vocal duties—Stereo was built from the ground up to be a collaborative hub. Rather than acting as a traditional frontman-led band, Hakanen and Marttila positioned themselves as producers and curators, inviting a rotating roster of Finland’s elite musical talent to lend their voices to the tracks.

Collaborations and Chart Success

Stereo’s output was defined by a high-frequency release strategy and a star-studded lineup of guest features. Their debut single, “Vuosien päästä” (featuring rising pop star Etta), immediately caught fire, dominating Finnish radio play and securing a multi-month stronghold on Spotify’s top charts. The track ultimately achieved platinum status, proving that the duo’s pop sensibilities translated seamlessly from rock guitars to electronic production.

Following this explosive debut, Stereo kept the momentum alive by releasing a steady stream of singles, often dropping a new track every month leading up to their debut album. Their roster of collaborators read like a who’s who of modern Finnish music:

• Samu Haber (formerly of Sunrise Avenue) on “Sä saat mut palasiksi”
• Michael Monroe (legendary Hanoi Rocks frontman) on “Woo Woo”
• Aste, Teflon Brothers, Sini Yasemin, Ida Paul & Kalle Lindroth, and others

This collaborative spirit extended to the production table as well. For instance, their single “Sä saat mut palasiksi” was mixed by Miles Walker—a top-tier mixer whose credits include heavyweights like Beyoncé, Bruno Mars, Coldplay, and Rihanna. This injected an international, polished pop sheen into the duo’s Scandinavian electronic roots.

The Album 00740 and Live Spectacle

In late 2019, Stereo encapsulated their electronic excursion by releasing their debut studio album, 00740. The album cemented their ability to blend infectious hooks with hard-hitting electronic drops, bridging the gap between underground club music and mainstream Finnish radio pop.

To support the release, Stereo transitioned from the studio to the stage, embarking on an extensive 26-date autumn tour across Finland. The era culminated in a high-energy celebratory finale at Helsinki’s iconic Tavastia Club in December 2019.

A Temporary Spark, A Lasting Impact

True to its initial design, Stereo was conceived primarily as a chapter to fill the Haloo Helsinki! hiatus. Once that downtime concluded, Hakanen and Marttila returned to their primary home in Haloo Helsinki!, leaving Stereo as a fascinating, brilliantly executed side project that showcased their versatility as musicians, writers, and producers.

Though brief, Stereo proved that great songwriters can bend any genre to their will. By stepping out of their comfort zone and embracing the electronic unknown, Hakanen and Marttila gave Finnish pop fans a high-octane project that remains a standout chapter in modern domestic music history.