If you have any serious interest in modern pop music, Broadway or rock, you really should not just read, but actually own a copy of Walter Rimler's 1984 book Not Fade Away. I consider it a basic reference book.
The author sets up the book as a compare and contrast between a half dozen of the main Broadway writers (including Berlin, the Gershwins and Harold Arlen) versus a half dozen major rock era composers (including Dylan, Paul Simon and Holland-Dozier-Holland). Besides specific commentary on the work of the individual songwriters, he bounces the groups off one another quite effectively to give a picture of the relative strengths and weaknesses of the old versus new ways of doing things.
He accomplishes this through musical analysis that hits just the right tone. He knows enough music theory to explain fairly specifically what kind of special tricks the composers are doing, but doesn't go so far as to lose the comprehension of non-scholars.
Over a period of several years, this book has really helped me to appreciate the Broadway song tradition, and improved my understanding even of the rock era.
This book certainly belongs on the shelf of absolutely everyone who writes pop songs.