Born in 1946 in Aizpute, Latvia (then a part of the Soviet Union) as a son of the Protestant minister. He attended the Riga Music Academy and the Lithuanian Music Academy in Vilnius where he studied double-bass with Vitautas Sereika until 1970. During his studies in Vilnius he came into contact with the music of the Polish avantgarde. In 1970-72 he served in the Soviet Army. He subsequently studied composition with Valenzius Utkin at the Latvian Academy of Music in Riga (1973-78). From 1963 to 1974 Vasks was a member of various symphony and chamber orchestras such as the Lithuanian Philharmonic Orchestra (1966-69), the Latvian Philharmonic Chamber Orchestra (1969-70) and the orchestra of Latvian Radio and Television (1971-74). He made his first trip to the West in 1989.
His compositions are profusely imbued with archaic Latvian folk elements and most of them have programmatic titles, which refer to nature. But what really matters to Vasks is not so much the poetic praise of nature or description of landscape as an aesthetic ideal but rather the harmonious relationship between man and nature, as well as the ecological and moral threats which are likely to destroy this relationship. In 1994 Vasks was made an honorary member of the Latvian Academy of Sciences, and in 2001 of the Royal Swedish Academy of Music. His honours also include the Grand Lithuanian Music Award for the choral piece Litene (1993) and the Latvian Music Award for the Violin Concerto 'Distant Light' (1998). He received the Herder Award from the University of Vienna in 1996 and was the featured composer at the New Music Festival in Stockholm in the same year.
He lives and works in Riga.

Selected works (since 1980): Landscape with Birds for solo flute (1980), Die Jahreszeiten I: Weisse Landschaft for piano (1980), Die Jahreszeiten IV: Herbstmusik for piano (1981), Message for strings, percussion and two pianos (1982), In Memory of a Friend, quintet for wind instruments (1982), Musica dolorosa for string orchestra (1983), Little Summer Music for violin and piano (1985), Episodi e Canto perpetuo for violin, cello and piano (1985), Lauda for orchestra (1986), Sonata for Solo Double-bass (1986), Concerto for Timpani and Percussion (1979-86), Latvija, chamber cantata for soprano, flute, bells and piano (1987), Spring Sonata for two violins, two violas and two cellos (1987), Musica seria for organ (1988), Musique du soir for horn and organ (1988), Concerto for English Horn and Orchestra (1989), The Sonata of Loneliness for guitar (1990), Balsis ('Voices') - Symphony for Strings (1991), Pater noster for a cappella choir (1991-95), Te Deum for organ (1991), Landscapes of the Burnt-out Earth, fantasy for piano (1992), Litene, ballad for mixed choir, to texts by Knuts Skujenieks and Leons Briedis (1993), Cello Concerto (1993-94), Die Jahreszeiten II: Frühlingsmusik for piano (1995), Three Poems by Czesław Miłosz for four solo voices and a cappella choir (1995), Musica adventus for string orchestra (1995-96), Distant Light - Violin Concerto (1996-97), Dona nobis pacem for mixed choir and string orchestra (1996), Symphony No. 2 (1998-99), Mass for a cappella choir (2000), Viatore per orchestra ad archi (2001), Partita for Cello and Piano (2001), Piano Quartet (2001), String Quartets Nos. 2-4 (1984, 1995, 1999).

Musica adventus is an arrangement of the String Quartet No. 3 from 1995. In view of its Shostakovich-like intensity and weight, it may be called the second Symphony for Strings (Balsis of 1991). The material is taken from the Gospel ('...and on earth peace to men of good will'), but the music is full of vivacious, dance elements (Scherzo) and folk motifs.