Francisco Correa de Arauxo
Correa only seems to have published one collection of organ works.  It was called Libro de tientos y discursos de música practica, y theorica de organo intitulado Facultad organica (1626).  This was a collection of organ music, as well as a discussion about music theory.  It is one of the few books we have which shows us what musical composition was like in Spain at that time.  His organ music uses a divided keyboard (medio registro), so that the upper and lower parts of the keyboard (high notes and low notes) can use different stops (making different sounds).  The organ pieces in the collection are arranged in order of difficulty.  The pieces at the end are very hard indeed. He uses a lot of dissonances, and he expects the performer to put in lots of ornaments, even if they are not shown in the music.  He uses glosa (ornamental figuration), although he also uses counterpoint.  His harmony shows the influence of composers such as Cabezon and Aguilera de Heredia.