Liljefors studied in Uppsala with Ivar Eggert Hedenblad until 1895, and subsequently in Leipzig with Salomon Jadassohn until 1899. Later he attended the Stockholm Conservatory. He completed his education with Felix Draeseke, Max Reger, and Hermann Ludwig Kutzschbach. From 1902 to 1911, he conducted the choir and orchestra of the Gothenburg Philharmonic Society. Afterwards, he moved to Gävle to conduct the Gävleborg County Orchestra between 1912 and 1931; he also served as a music teacher at the Gävle higher general secondary school during this time.
Song at the dedication of the repaired building of the Uppland Nation (T. Tullberg), for male choir (1902)
Flower Festival (C. Snoilsky), soprano and alto solo, mixed choir and orchestra (1907)
Cantata for the inauguration of Gothenburg University's new Academy Building (A. U. Bååth) soprano, baritone, and tenor solo, mixed choir, male choir, and orchestra (1907)
Bohuslän, Anniversary at the 250-year anniversary of the Peace of Roskilde (E. Evers), solo, mixed choir and organ (1908)
Cantata for Heimdal's 40-year anniversary (S.H.T.-kantat, Bååth), male choir and piano (1908)
Hymn for the Lambert Fair (E. A. Karlfeldt), mixed choir and orchestra (1908)
Cantata for the inauguration of the Gävle Polytechnic's Refurbishment (M. Sterner), tenor solo, mixed choir, blandad kör, boy's choir and orchestra (1914)
For the Home District (H. Hamilton), baritone solo, mixed choir and orchestra (1914)
Chamber music
Violin Sonata in E major, Op. 2 (1895)
Piano music
Menuett, WoO (1886)
Wedding March (for his brother Carl's wedding, 1893)