Alec Wilder (1907–80) constructed his autobiographical book Letters I Never Mailed in 1975 as a set of “letters” to the friends, associates, and individuals who had been a part of his life. The letters appear to have been written over the span of Wilder's life, but in reality they were composed for the purpose of this book. He created an ingenious format that defies literary category. So ingenious, in fact, that the identity of many of the addressees was at times—purposely or not—lost on readers who were unfamiliar with the personal details of Wilder's truly unique life. That life traversed an amazing span of American culture, including literary society, the Algonquin Hotel, popular songwriting, opera, chamber music, jazz and cabaret, theater, and film. Some of Wilder’s letters are hilarious, self-deprecating, and light-hearted; others contain his deepest, most heartfelt views on life, art, and music. Many are warm and affectionate, some are angry, and a few are embarrassingly private. Many letters are addressed simply to the person's first name.

In this annotated edition an Annotated Addressee List is provided which gives as many addressee identities as possible and “decodes” the letters, putting them into the context of Wilder’s life. The Introduction draws upon Wilder's own words from his two unfinished autobiographical works, “The Search” (handwritten in two notebooks, 169 pages, 1970) and “Life Story” (typescript, 189 pages, 1971), both written just prior to this book. While Wilder's literary motivation for these two book-length pieces is not clear, the first work may have served as journal notes for the second, or both may have taken on that function as he worked on Letters I Never Mailed a few years later. Both are unpublished, and are still in their original form, housed in the Alec Wilder Archive at the Sibley Music Library of the Eastman School of Music.

Also included are a number of photographs taken by photographer Louis Ouzer (1913–2002), a lifelong Wilder friend, associate and collaborator. Ouzer and Wilder met as young men, and Ouzer's keen photographic eye and his equally clear perception of Wilder provide more clues to Wilder's life and complex personality. Complementing Ouzer's images are newly rediscovered school photos of Wilder that show him as a boy and young man.

Alec Wilder's original version of Letters I Never Mailed exists in this annotated edition unchanged, letter for letter.