Costas Baltazanis studied jazz guitar performance and composition at Berklee College of Music in Boston.
In 1995, he formed the band Iasis, along with Petros Kourtis on percussion and Yiotis Kiourtsoglou on bass. The group was performing his compositions in the field of world fusion and collaborated with artists such as Faruk Tekbilek, the Bulgarian Voices, David Lynch, Takis Paterelis and Sokratis Sinopoulos. he band’s homonymous first album was released in 1996 and was succeeded by "Amalgama" (1998) and "Duente" (2002).

In 2002, he composed the music for the movie "Paradise is a Personal Affair".

He has performed in many countries and some of the artists he has played with are Alex Foster, The Charles Mingus Orchestra, Arturo Sandoval, David Friedman, Jeff Tain Watts, James Genus, Mike Wolff, Kenwood Dennard and The Stuttgart Symphony Orchestra.

His personal album "End of Seas", which among others featured Alex Foster and Camila Meza, was released in 2015.
In 2016 he created the experimental jam band Subtonics. Their first album "Vinyl" was released in 2019.