was born in 1978 in Riga. He studied composition at the Latvian Music Academy in 1996–2003. In the years of 1998–99 a scholarship enabled him to study with Sven-David Sandström at the Royal College of Music in Stockholm and in 2004–07 he completed his post-graduate degree with Ole Lützow-Holm at the Academy of Music and Drama in Göteborg.

Jānis Petraškevičs attended courses in Schwarz/Tyrol (1996), Darmstadt (1998) and Royaumont (2000), he also worked at the Academy Schloss Solitude in Stuttgart (2003) and at the EarLab in Stresa (2008). In 2001 he received a commission from the Ensemble intercontemporain (trop proche/trop loin). His Opus 2 et la nuit illumina la nuit won the composition contest of the Association of Baltic Academies of Music in 2003. His works were performed in 2008 at the Venice Biennale and ISCM Festival in Vilnius. Renowned ensembles, including Ensemble Ictus, Ensemble intercontemporain, Ensemble SurPlus, or Ensemble Modern have incorporated the works of the 34-year old composer in their repertoires.

Selected works: Et la nuit illumina la nuit for clarinet, viola and piano (1997), Flight of the Arrow. Just Heaving in Sight and... Far Afar for cello (1997), Mist...the Furthest Point for ensemble (1998), Distance(s) for strings (1999), trop proche / trop loin for 15 musicians (2002), Arktos for 7 musicians (2002), Mezzogiorno for ensemble (2005), Translated into the Language of Memory (Part 1 – Reading the Silence) for orchestra (2007), Fragile for violin and 8 instruments (2008); Darkroom for ensemble (2012).