▁of ▁ad oring ▁hearts ▁( cf . ▁cont rap unt al ▁or ▁poly ph onic ▁music ). ▁Besides ▁plain ▁chant ▁and ▁the ▁poly ph onic ▁style , ▁the ▁Catholic ▁Church ▁also ▁perm its ▁hom oph onic ▁or ▁figured ▁compos itions ▁with ▁or ▁without ▁instrument al ▁accompan iment , ▁written ▁either ▁in ▁ecc les iast ical ▁modes , ▁or ▁the ▁modern ▁major ▁or ▁minor ▁keys . ▁Greg or ian ▁chant ▁is ▁warm ly ▁recommended ▁by ▁the ▁Catholic ▁Church , ▁as ▁both ▁poly ph onic ▁music ▁and ▁modern ▁un ison ▁music ▁for ▁the ▁assembly . ▁ ▁Prior ▁to ▁the ▁Second ▁V at ican ▁Council , ▁according ▁to ▁the ▁mot u ▁proprio ▁of ▁P ius ▁X ▁( Nov ember ▁ 2 2 , ▁ 1 9 0 3 ), ▁the ▁following ▁were ▁the ▁general ▁gu iding ▁principles ▁of ▁the ▁Church : ▁" S ac red ▁music ▁should ▁possess , ▁in ▁the ▁highest ▁degree , ▁the ▁qual ities ▁proper ▁to ▁the ▁lit ur gy , ▁or ▁more ▁precisely , ▁san ct ity ▁and ▁pur ity ▁of ▁form ▁from ▁which ▁its ▁other ▁character ▁of ▁univers ality ▁sp ont ane ously ▁spr ings . ▁It ▁must ▁be ▁holy , ▁and ▁must ▁therefore ▁exclude ▁all ▁prof an ity , ▁not ▁only ▁from ▁itself ▁but ▁also ▁from ▁the ▁manner ▁in ▁which ▁it ▁is ▁presented ▁by ▁those ▁who ▁execute ▁it . ▁It ▁must ▁be ▁true ▁art , ▁for ▁otherwise ▁it ▁cannot ▁exercise ▁on ▁the ▁minds ▁of ▁the ▁hear ers ▁that ▁influence ▁which ▁the ▁Church ▁med it ates ▁when ▁she ▁wel comes ▁into