A fake book is a collection of musical lead sheets intended to help a performer quickly learn and perform new songs. Each song in a fake book contains the melody line, basic chords and sometimes lyrics – the minimal information needed by a musician or small group to make an impromptu, extemporized arrangement of a song, or "fake it". The fake book is a central part of the culture of playing music in jazz, where strong improvisation abilities are expected from "comping" rhythm section players (piano, electric guitar, double bass, drum kit) and "lead instruments" which play the melody and improvise lengthy solos over the chord progression.
Fake books are not intended for novices. Sometimes, melodies with syncopation are written with the syncopation omitted, so the reader must be familiar with the songs "by ear" to play the melodies correctly. Some 32 bar forms do not have a printed melody during the "B" section, as the lead instrumentalist is expected to improvise one. Similarly, the chord progressions for some blues tunes omit the turnaround (often simply indicating two bars on the tonic), as it is expected that an experienced jazz player will know the appropriate turnarounds to insert (e.g., (I–VI7–ii–V7). The reader needs to have thorough familiarity with extended chords (e.g., C13) and altered chords (e.g., C7♯11). Introductions and codas are often omitted, as it is expected that players will know the familiar intros and codas used on specific songs. Fake books are often bound.
A variant type of fake book contains only the chord progressions to the songs. These books could be used by the rhythm section instruments to guide their improvised accompaniment and by "lead instruments" for their improvised solo sections, but since they do not contain the melody, they can be used in performances only by players who have the melodies memorized. Fake books are commonly used at informal "jam sessions" and at jazz shows at small nightclubs and bars.
A predecessor to fake books was created in May 1942 when George Goodwin, a radio station director, released the first Tune-Dex cards. Printing on 3-by-5-inch (7.6 by 12.7 cm) index cards that had the same size as library catalog cards, Goodwin provided lyrics, melody and chord symbols as well as copyright information. Goodwin also promoted the cards to professional musicians until 1963, when poor health forced his retirement. For many years the "standard" fake books were called simply "Fake Books". All were composed of songs illegally printed, with no royalties paid to the copyright owners. In 1964, the FBI's Cleveland, Ohio, office observed that "practically every professional musician in the country owns at least one of these fake music books as they constitute probably the single most useful document available".
The first two volumes, Fake Book Volume 1 and Fake Book Volume 2, issued in the late 1940s–1950s, together comprised about 2000 songs dating from the turn of the 20th century through the late 1950s. In the 1950s the Modern Jazz Fake Book, Volumes 1 and 2 was issued, and Fake Book Volume 3, containing about 500 songs, came out in 1961. The music in Fake Books 1, 2, and 3 was photocopied or reset with a musical typewriter from the melody lines of the original sheet music. Usually chord symbols, titles, composer names, and lyrics were typewritten, but for a number of songs these were all photocopied along with the melody line.
The chord changes in these books were notoriously inaccurate. Most of them were based on the guitar and ukulele chords commonly found in earlier sheet music, which often did not include the roots of the harmony. For example, a chord labeled "Fdim" ("F diminished") for guitar or ukulele might functionally be a G7♭9 ("G seven, flat nine") chord, which has a G as the root plus all the notes of an Fdim7 chord. Thus, successfully using the Fake Books required the expertise of jazz musicians and others trained in functional harmony in order to reinterpret the chord symbols.
The three Fake Books were well indexed, alphabetically as well as by musical genre and Broadway show. Although the tunes in the Fake Books were compiled illegally, the creators printed copyright information under every song – perhaps to give the false impression that the Fake Books were legal, or to show respect for the creators. The Modern Jazz Fake Book was divided into two sections, each indexed separately as Volume One and Volume Two. The music was transcribed by hand from recordings, and each transcription included performer name, record label, and catalog number. Unlike today's fake and "real" books that have "jazz" in their titles, the Modern Jazz Fake Book included no standards, but only original tunes written and recorded by jazz musicians. All these books have been long out of print, though music students have photocopied the books from other musicians. Fake books originally infringed copyrights, and their circulation was primarily underground.
During the school year of 1974–75, an unidentified group of musicians based at the Berklee College of Music in Boston published The Real Book, which claimed to fix all problems of poor design, although it was riddled with errors, which were gradually corrected by generations of players. Steve Swallow, who was teaching at Berklee at that time, said the students who edited the book intended "to make a book that contained a hipper repertoire, more contemporary repertoire". Alongside the standard tunes of previous decades were lead sheets for compositions by then-contemporary jazz fusion composer-performers such as Keith Jarrett, Herbie Hancock, Chick Corea, Joe Henderson, Wayne Shorter, Carla Bley, Pat Metheny, Mike Gibbs, Ralph Towner and Steve Swallow (amongst others). It was popular and in its turn spawned a number of "fake Real Books".
In the 2000s, some types of "real books" have been published which fully respect copyright laws. In the 2000s, some computer-based "fake books" became available. Since these computer-based fake books are stored on a computer, the user can have the key transposed instantly. This facilitates the performance of music at shows where some performers have transposing instruments, or in shows with a singer who wants the band to play in a different key to accommodate their vocal range. Examples of such transposable charts software are Jazz studies (web based) and Fakebook (Android app).