Biber's compositions stand as some of the most startlingly advanced music of the Baroque era. Biber's manuscripts and publications record violin improvisations in unprecedented detail; in his Sonata Representativa, one will find Biber's instrumental impressions of cuckoos, frogs, cats, and marching musketeers. These are supplied with a simple ground bass that provides plenty of room for the soloist to stretch out and show off, but are written at such a high level of difficulty that few violinists attempt to master them. In his "Mystery", or "Rosenkranz" sonatas, Biber makes extensive use of scordatura, violin re-tunings that change the tonal character of the instrument and make "impossible" figurations possible.
Biber was clearly influenced by the Musurgia Universalis, a theoretical work written by German Jesuit scientist and mathematician Athanasius Kircher. First published in 1650, Kircher draws parallels between musical tones, planetary motion, and psychological states of being. Biber's music is strongly affective emotionally, and in works of a programmatic character, such as his orchestral piece Battalia, he attempts to combine both a literal and subjective listening experience. In Battalia, the orchestra is required to play several marching songs in different keys at once -- in a manner similar to the music of Charles Ives
-- to indicate eager soldiers of various regiments leading off to battle. A soft, hushed passage at the end of the work represents the result, a somber tableau of battlefield dead.
Biber also composed a number of sacred vocal works; most of these reside easily within the required strictures of the Church. A standout piece is his 15-part requiem, an expressive and harmonically adventurous mass that eschews the sobriety of the text in favor of glorious antiphonal choral textures. Along those same lines, musicologists have established that the anonymous, huge 53-part Missa Salisburgensis is also likely the work of von Biber.