He was born in Portland, Oregon. He was Battell Professor of Music, Emeritus at Yale University. Forte is arguably best known for his book The Structure of Atonal Music, in which he extrapolates from the serial theory of Milton Babbitt, proposing a musical "set theory" of pitch-class-set analysis analogous to mathematical set theory with the avowed intention of providing a method for the analysis of non-serial atonal music. The musicologist Richard Taruskin and the composer and music theorist George Perle are among the most vocal critics of this method. Forte was also the editor of the Journal of Music Theory during an important period in its development, from volume 4/2 (1960) through 11/1 (1967). His involvement with the journal, including many biographical details, is addressed in David Carson Berry, "Journal of Music Theory under Allen Forte's Editorship," Journal of Music Theory 50/1 (2006): 7-23.
Forte published analyses of the works of Webern and Alban Berg and has written about Schenkerian analysis and American popular song. A complete, annotated bibliography of Forte's publications appeared in David Carson Berry, "The Twin Legacies of a Scholar-Teacher: The Publications and Dissertation Advisees of Allen Forte," Gamut 2/1 (2009), 197-222, accessible at . Excluding items only edited by Forte, it lists ten books, sixty-three articles, and thirty-six other types publications, from 1955 through early 2009. The article also provides a list of all seventy-two of Forte's Ph.D. advisees at Yale University. The list is ordered chronologically by dissertation submission (which ranges from 1968 to 2002), and each advisee is given an "FA" number to denote his or her ordering among the advisees. ("FA" stands for "Forte Advisee," and is also a retrograde of Allen Forte's initials.)
Forte has been honored by two Festschriften (homage volumes). The first, in commemoration of his seventieth birthday, was published in 1997 and edited by his former students James M. Baker, David W. Beach, and Jonathan W. Bernard (FA12, FA6, and FA11, according to Berry's list). It is titled Music Theory in Concept and Practice (a title derived from Forte's 1962 undergraduate textbook, Tonal Harmony in Concept and Practice). The second was serialized in Gamut: The Journal of the Music Theory Society of the Mid-Atlantic, and commenced in vol. 2/1 (2009). It is ongoing, and is edited by Forte's former student David Carson Berry (FA72); it is titled A Music-Theoretical Matrix: Essays in Honor of Allen Forte (a title derived from Forte's 1961 monograph, A Compositional Matrix).
Forte fought in the Navy at the close of World War II before moving to the East Coast. He was married to the pianist Madeleine Forte.
- (1955) Contemporary Tone-Structures.
- (1962) Tonal Harmony in Concept and Practice.
- (1973) The Structure of Atonal Music.
- (1978) The Harmonic Organization of The Rite of Spring.
- (1982) Introduction to Schenkerian Analysis (with Steven E. Gilbert).
- (1995) The American Popular Ballad of the Golden Era 1924-1950. Princeton: Princeton University Press.
- (1998) The Atonal Music of Anton Webern.
- "In memoriam Allen Forte, music theorist". news.yale.edu. October 17, 2014.
-  The Allen Forte Treatise Collection at the Warren D. Allen Music Library at Florida State University
-  Allen Forte Electronic Archive (AFEA): Unpublished papers, notes, sketches, and video clips available for viewing and download through the Center for Schenkerian Studies at the University of North Texas.