The Regina Caeli is one of four Marian antiphons traditionally said or sung after compline. It is said throughout Eastertide – the fifty day period from Easter Sunday to Pentecost, and during that period can be said in place of the Angelus. Philips' setting while it is for two choirs is more Roman than Venetian in its style it was a moderately conservative piece for its time eschewing the extremes of dissonance and chromaticism that were so popular amongst the Italian avant garde. Instead Philips made use of highly coloured and expressive harmonies and confined his use of contrapuntal imitation to the antiphon's opening bars. Philips as a loyal Catholic who had fled his native England in order to freely practice his faith was determined that his music would uphold and glorify the teachings of the Church particularly the one which held that any sung texts should be clearly discernible. I think he succeeded very well the text being sung is clear and is clearly illustrated, so despite the various compositional tricks that he employed such as contrasts between long and short notes and the passing of phrases from one side to the other, the congregation could easily follow and absorb the text and its musical illustration. It's a joyous piece sung at a joyful time the effect on his listeners isn't recorded but it have been almost like listening to a madrigal. Enjoy :-).