Abacab is the eleventh studio album by English rock band Genesis, released on 18 September 1981 by Charisma Records.

The album was certified gold in the UK and double platinum by the Recording Industry Association of America for selling two million copies in the US.

In June 1980, the Genesis line-up of drummer and singer Phil Collins, keyboardist Tony Banks, and guitarist/bassist Mike Rutherford, with touring drummer Chester Thompson and guitarist and bassist Daryl Stuermer, wrapped their 1980 tour of the United Kingdom and North America in support of their tenth album, Duke (1980).

Following a period of rest, in November 1980 the band bought Fisher Lane Farm, a farmhouse with an adjoining cowshed near Chiddingfold, Surrey, as their new private rehearsal and recording facility.

The success of Collins's debut solo album Face Value (1981) had gained momentum by the recording stage; Banks claimed it did little to alter the sound or style of Abacab or the relationship towards him or Rutherford as they had been friends for a long time.

Though the band did not alter the way in which they approached the songwriting for Abacab,[6] Banks said a conscious effort was made by the group to avoid "Genesis cliches" such as using tambourines during a chorus, reprises, extended solos, lengthy instrumental passages,[7] and keeping melodies simple, which signalled further changes in their direction.

[12] The home studio allowed the group to stop working on a track if a rehearsal failed to produce any desired results and switch to another, which was not possible at a professional facility due to the limited time available.

[13] Gabriel's track "Intruder" features a gated reverb effect on Collins's drums that Banks and Rutherford liked, and wanted Padgham to do the same on Abacab.

[14] The decision to bring the drums to the forefront of a song caused Banks to change his usual approach of writing and playing, which he found exciting.

[6] Abacab is formed of nine tracks, six of which are group written with the remaining three solely credited to one of each member: "Me and Sarah Jane" is from Banks, "Man on the Corner" by Collins, and "Like It or Not" by Rutherford.

"[12] The song developed from a group jam session that had them playing along to a looped electronic drum track until the tape they were using to record on ran out.

[6] "No Reply At All" is a rhythm and blues style track that features the Phenix Horns of the American band Earth, Wind & Fire.

[18] The band wanted to emulate the brass keyboard sound that was used on some parts on Duke, and Collins had used the Phenix Horns on Face Value and suggested to Banks and Rutherford that they use them for the track.

Collins thought the horns was a good move to "suddenly jar people and take them off automatic pilot" from the preconceived notions they had about Genesis.

[7] Featuring drums, guitar, and a Prophet-5 analogue synthesiser, he obtained the track's distorted keyboard sound by changing its presets as he played the notes.

[24] While the group were deciding the final track listing for Abacab, Atlantic Records president Ahmet Ertegun believed "Who Dunnit?"

Two other songs, "Naminanu" and "Submarine", originally part of a four-song suite with "Dodo"/"Lurker", were released as B-sides on the album's singles.

Rutherford took Smith's sketchbook and spotted an abstract design initially made for a book, which featured an arrangement of torn inch-long pieces of paper from a Pantone swatch of colours with squiggly black lines.

Colbert, however, thought Genesis had produced "a couple of Frankensteins" such as the latter half of "Abacab", which he deemed "unstructured" and "uninspired" compared to their past instrumentals.

[33] Jim Bohen for Daily Record recognised Abacab had largely taken its direction from Collins's Face Value with its structure based around a "a huge, booming drum sound".

[29] In his retrospective review for AllMusic, critic Stephen Thomas Erlewine echoed this sentiment with greater emphasis, declaring "Duke showcased a new Genesis... but Abacab was where this new incarnation of the band came into its own."

[38] Additional songs recorded during the Abacab sessions can be found on other releases: Credits are adapted from the album's sleeve notes.