Mustajärvi was born on 12 July 1956. He appears in the 1984 film
Calamari Union by
Aki Kaurismäki, playing one of the fifteen main characters named Frank. In 2004 Mustajärvi performed two songs on the soundtrack of the Finnish action-
thriller film
Vares – yksityisetsivä. Mustajärvi released two cover albums in consecutive years, the first in 2009 featuring songs from his longtime friend
Juice Leskinen, the other in 2010 dedicated to translations of
Johnny Cash songs into Finnish. Mustajärvi died on 26 December 2025, at the age of 69. ==Discography==