Facts Behind the Songs by Marvin E. Paymer is an idiosyncratic reference book for popular music. Its scope is the music from the 1890s (the earliest days of Tin Pan Alley) to the early 1990s. The books consists of alphabetical succession of articles by 11 contributors that are classified into 8 categories: 1) origin; 2) foreign influence; 3) domestic influence; 4) dissemination; 5) historical survey; 6) genre; 7) song subject; and 8) style of music and lyrics.
"Origin" brings together articles relating to the creators and the production of music. Some articles are about locales, others are about venues for creation.
"Foreign Influence" looks at the contribution of other cultures in American popular music. Domestic Influence likewise considers how American genres (ranging from Bebop to Zydeco) entered the musical mainstream.
"Dissemination" looks at technology and the institutions that offer music. The "Historical Survey" devotes a chapters to a variety of time periods; genre lists articles on a variety of styles of music.
Perhaps the most useful category is "Song Subject." There are articles about more than 100 categories ranging from "age" ("Forever Young," "My Generation") to "writing" ("Take a Letter, Maria," "Paperback Writer"). I have found this book to be helpful for the article "Classics" which includes a table called "The Classics and Popular Song." This provides a convenient listing of classical melodies that have become popular songs.
The book closes with a "Catalogue of Songs" that lists every song mentioned in the book giving the year it was written and the names of the songwriters. It also indexes every article where each song is mentioned.
The information in Facts Behind The Songs is mostly covered in other reference sources. The value of the book is the unique organization of this information.