Illumina nos is the final “sacred song” in a book of twenty printed in Naples by Constantino Vitali and published there in 1603 by Don Giovanni Pietro Cappuccio. It is the only piece in the book requiring seven voices: the others are six-part polyphony. In the same year the same printer and publisher brought out a volume of nineteen five-voice “sacrae cantiones” by Gesualdo. Both of these volumes were marked “Liber Primus,” but if other books were published no copies are known to survive. Then in 1611, Giovanni Jacomo Carlino printed in Naples a book of twenty-six six-voice “Responses” by Gesualdo. These three volumes contain all that is known of Gesualdo's sacred music, and the only known copies of these volumes are in the library of the “Oratorio dei Filippini” at Naples. In 1934 Guido Pannain included fourteen of the five-voice sacred songs in a collection of “La polifonia cinquecentesca ed i primordi del secolo XVII di Napoli.” At this time Pannain discovered that the sextus and bassus parts of the six-voice volume were missing (a catalogue of the “archivio dell” oratorio Filippini” listing all three volumes had been published in Parma in 1918, but apparently no one before Pannain had examined the music). Not until 1955 were photo copies obtainable of the other “sacred songs” and of the “Responses.” Since then Mrs. Ruth Adams of the University of California in Los Angeles has transcribed the five five-voice pieces not published by Pannain, and the whole book of “Responses“ which includes a psalm setting and part of a Tenebrae Service.