Guerau probably served in the Spanish court since c. 1659. His passacalles for the guitar were highly lauded particularly by the guitarist Santiago de Murcia.
The collection "Poema harmonico" had twenty seven compositions for the guitar specifically in the Baroque style. Included are instructions concerning tablature, technique and embellished performance. The guitar was probably a ten-stringed instrument with the tuning A/a, d/d', g/g, b/b, e'. Most of the pieces were in the minor key and pizzicato. ~ Keith Johnson, Rovi