I can’t seem to find a specific passage where this was mentioned, but it does sound like a CM principle.
We usually have several read-alouds going at one time.
-one or two history read-alouds (a spine and a separate book about the specific historical event we’re studying)
-a nature read-aloud about the season or an animal we’re studying
-a literature read-aloud (in our family, this is with Daddy at bedtime)
-perhaps a biography of the artist or composer we’re learning about, with only a few pages read each week
-a faith or religion book, such as Bible stories, a book about character, a saint biography, etc.