2015 Ari started to perform at the "Music Theater Palatsi" in Tampere, Finland. The theatre changed its name to Finnish Music Theatre, Suomen musiikkiteatteri in 2017. Their first play with Ari was the rock musical "I Wanna Rock" in 2015, where he plays the roles of Michael Monroe, Axl Rose and Steve Perry. He went on playing in the theater also 2016 in a musical called "Autiotalossa" where he plays the name role of the legendary Finnish rock musician Neumann from the band Dingo in the 80's. In winter 2017 there was a premiere of "We Rock! Heavyrock Night", where Ari and 5 other singers sing legendary heavy metal songs. In autumn 2017, there was a premiere of the Finnish 70's retro rock musical "Raparperitaivas", where Ari plays one of the main roles.