Valo has collaborated with many different artists during his career, often under different pseudonyms. Between 1997 and 2004, Valo performed back-up vocals on five albums by The 69 Eyes, and appeared in the music video for the song "Wasting the Dawn". In 1999, he sang back-up on Tehosekoitin's album "Freak Out", and performed three songs with Finnish Schlager band Agents. In 2000, Valo contributed a track for the Tuomari Nurmio tribute album "Tuomarin todistajat", and in 2001, he played drums on Daniel Lioneye's album "The King of Rock 'n Roll" and sang back-up on Five Fifteen's album "Death of a Clown". In 2002 and 2004, Valo sang back-up on two albums by The Skreppers. In 2004, he also collaborated with Lowe Motor Corporation and Apocalyptica, performing the song "Bittersweet" with the latter, which also featured Lauri Ylönen of The Rasmus. In 2005, Valo was featured on the album "Hefty Fine" by the Bloodhound Gang, and performed at the "Roadrunner United" concert in New York City.