Esa Pietilä (b. 1964) started his jazz career similarly as many of his collegues, by playing saxophone in a big band. From Pori Big Band he moved to play in Turku Big Band and Settlement Big Band and finally ending up playing in Espoo Big Band. The first international jazz performances of Pietilä were with Espoo Big Band as the orchestra did co-operation with i.a. Thad Jones, Art Farmer and Carla Bley. The first rcording for the saxophonist was EBB's and Sakari Kukko's Moonlight Caravan & Finnish Characters in 1990.

Pietilä started his studies at the jazz department of Sibelius Academy in 1987 and founded his own quartet a couple of years later, that performed around Finland actively. In 1996 after graduating from Sibelius Academy, saxophonist expanded his quartet into a sextet and named it The Case that released the album Codes in 1997 (Trick Music) that included many unique compositions by Pietilä. The expression of The Case was electronic and some songs had even programmed sequencebacksgrounds. The next album of the saxophonist, with a quartet set up specially for the album, was an acoustic record Fastjoik (A-Records 1998) that had Pietilä's diverse compositions, interpreted smoothy by the band, as it's core. Pietilä's compositions on this album got lots of good feedback from the critics of Finnish and international jazzmagazines.

In 2001 Pietilä formed a trio with bassist Ulf Krokfors and drummer Markku Ounaskari. The expression was a lot more freer than before and the material in the compositions was trimmed to include only the essential, the themes. Pietilä's skills were noticed in this challenging line-up and he proved to be a great free jazz saxophonist. Trio performed for the first time in 2001 and released it's debutalbum Direct (Fiasko Records 2003) a couple of years later.

The trio has been the main group for the saxophonist through the whole 21st century. The band did a tour organized by the Finnish Jazz Federation in spring 2004 and has performed abroad regularly. Once in a while the trio has been extended with featuring soloists, like guitarist Raoul Björkenheim. Pietilä's trio worked with the original line-up 'til 2009 and ever since Ounaskari and Krokfors have been replaced by younger musicians, bass player Ville Herrala and drummer Mika Kallio. Other groups for Pietilä, besides many duos with international artists, have been the Brain Inventory Trio formed with American pianist Michael Jefry Stevens and Finnish cellist Juho Laitinen, and 4 STREAMS with pianist Iro Haarla, Markku Ounaskari and Ulf Krokfors.

Other internationally known musicians that have done co-operation with Pietilä are i.a. Michael Jefry Stevens, Mathias Eick, Jeff Siegel, Harvey Sorgen, Karl Berger, Mark Helias, Brian Melvin, Heiri Kaenzig, Raoul Björkenheim, Christoph Baumann, Baenz Öster, Franziska Baumann, Mike Nock, Ron McClure, Claudio Fasoli, Jaak Sooäär, Anders Begcrantz, Odean Pope, Raoul Björkenheim, Iro Haarla, Filip Augustson, John Esposito, Hilmar Jensson, Kjartan Valdemarsson, Fabian Kuratli and Arthur Kell.