Complex sentence: On November 13,2009 it was announced that Def Jam Recordings would issue a box set of Rihanna's first three studio albums to accompany the release of her then-upcoming fourth studio album "Rated R" (2009).
Split into simpler sentences: On November 13,2009 it was announced that Def Jam Recordings would issue a box set containing Rihanna's first three studio albums. The set was to accompany the release of her then-upcoming fourth studio album "Rated R" (2009).