Behind the Synth-Pop Veil: The Story of Stereo, the Secret Project from Haloo Helsinki! Masterminds

When one of Finland’s biggest rock bands announced a sudden hiatus, fans experienced a mixture of shock and uncertainty. Haloo Helsinki!, the multi-platinum stadium-filling powerhouse, had been an unstoppable fixture of the Finnish music scene for over a decade. Yet, in 2018, guitarist Jere Marttila and lead guitarist/songwriter Leo Hakanen decided they needed a palette cleanser.

Enter Stereo (often referred to as Stereo yhtye), an electronic pop-dance side project that allowed two mainstream rock architects to step into the shadows, experiment with electronic soundscapes, and completely reinvent their creative process.

The Genesis: Stepping Out of the Arena and into the Club

For Marttila and Hakanen, writing and touring incessantly with Haloo Helsinki! had defined their youth and early adulthood. But the creative itch to explore contemporary electronic production, club beats, and a different vocal dynamic led them to form Stereo during the band’s 2018–2019 hiatus.

Rather than sticking to the organic guitars and heavy rock arrangements of their parent band, Stereo embraced a sleek, moody, and heavily synthesized aesthetic. The duo functioned as the primary producers and masterminds, but they made a deliberate choice to shift the spotlight away from themselves. Instead of standing front-and-center as traditional frontmen, they functioned as an elusive electronic production outfit, collaborating heavily with an all-star roster of Finnish vocalists.

The Sound and the Star-Studded Collaborations

Stereo’s self-titled debut album, 00740, dropped in 2019, accompanied by a wave of high-profile collaborative tracks that immediately caught the attention of Finnish radio and streaming platforms.

The project relied heavily on juxtaposition: cold, precise electronic beats paired with deeply emotional, melodic vocal performances from some of Finland’s most recognizable artists. Standout tracks from the project included:

• “Sä saat mut palasiksi” (featuring Samu Haber): A soaring, emotionally charged track that blended Haber’s distinct raspy delivery with sleek, modern club production.
• “Woo Woo” (featuring Michael Monroe): A high-energy collision of rock royalty and electronic groove, proving that the duo’s rock roots were never too far away.
• “Bonnie & Clyde” (featuring Ida Paul & Kalle Lindroth): A melodic, radio-friendly pop anthem exploring modern romance over driving synth rhythms.
• “Vuosien päästä” (featuring Etta): A brilliant showcase of bridging electronic pop with contemporary urban/rap sensibilities.

Through these collaborations, Stereo carved out a distinct identity that felt entirely separate from Haloo Helsinki!, trading organic arena-rock energy for a neon-lit, nocturnal atmosphere.

A Temporary Experiment with a Lasting Impact

In the grand tradition of successful side projects, Stereo was always conceptualized as a specific chapter rather than a permanent replacement. As the hiatus for Haloo Helsinki! concluded, Marttila and Hakanen returned to their main duties, bringing massive stadium crowds back into their primary focus.