Ask Mr Google for the "definition of a lyrical book" and you will not get a definitive answer. The top results on my search turned up phrases like:
                          song-like, poetic, deeply evocative
                                 beautifully full of emotion
                           effective use of poetic techniques
To the above, I say YES,YES, and YES! A well-written lyrical book contains all of these.

Two of my favorite lyrical books were written by Julie Fogliano. She is a former kindergarten teacher and an award-winning, New York Times best-selling author. Her picture books include a poetry collection and picture books that are rhyming and lyrical.