To suit the building's new purpose, the front-facing lecture hall's tiered benches were replaced so that the congregation was seated in the conventional position, facing away from the front, and a balcony was added.

[3] A public appeal was launched and in 1980, with the building renovated, the theatre opened with a festival of avant-garde music and performance, held both there and at other Islington venues, with Audi as the Artistic Director.

The Almeida International Festival of Contemporary Music and Performance included concert presentations and productions of new and commissioned operas from Europe, Russia, North America, Japan, Argentina, and Morocco.

Among the hundreds of composers, musicians and ensembles featured in frequent world and local premiere performances were Steve Reich, Philip Glass, Lou Harrison, Conlon Nancarrow, Morton Feldman, Elliott Carter, Virgil Thomson, Frederic Rzewski, Arvo Pärt, Alfred Schnittke, Wolfgang Rihm, Claude Vivier, Toru Takemitsu, Giacinto Scelsi, Michael Finnissy, Gerald Barry, Somei Satoh, Akio Suzuki, Takehisa Kosugi, Jo Kondo, Sylvano Bussotti, Luis de Pablo, Capricorn, Spectrum, Music Projects/London, Singcircle, the Arditti Quartet, and the London Sinfonietta.

Peter Greenaway's 1983 series of films for Channel 4 Four American Composers featured Almeida presentations of works by John Cage, Robert Ashley and Philip Glass.

For several years, the American pianist and composer Yvar Mikhashoff conceived and co-ordinated concert programming, including At the Tomb of Charles Ives: A Celebration of American Experimental Music 1905-1985 which featured world and UK premieres of works by Cage, Nancarrow, Glass, Feldman, Harrison, Rzewski, Charles Ives, George Antheil, Henry Brant, Anthony Braxton, Carla Bley, Roger Reynolds, Charles Wuorinen, and Lukas Foss and two piano marathons he performed himself: The Great American Piano Marathon: 70 works from 70 years in 7 Hours and 50 Tangos - 50 Composers - A Tango Marathon: Selections from the International Tango Collection.

Stage directors of Almeida Theatre Company productions included Pierre Audi, Ian McDiarmid, Yuri Lyubimov, Tim Albery, Mike Bradwell, David Hayman, and Jean Jourdheuil.

The 1985 Almeida Theatre Company production of The Possessed,[6] a co-production with the Théâtre de l'Europe in Paris which also toured to the Piccolo Teatro in Milan and the Teatro Comunale di Bologna, was Russian director Yuri Lyubimov's first to originate in the West after he defected in 1983[7] and featured music by Alfred Schnittke, design by Stefanos Lazaridis, and actors Nigel Terry, Clive Merrison, Harriet Walter, and Michael Feast.

Ronald Harwood's documentary drama, The Deliberate Death of a Polish Priest premiered at the Almeida in October 1985, an early example of a transcript of a trial of the political murderers of Father Jerzy Popiełuszko.

[13] The restoration included rebuilding and extending the foyer, installing more comfortable seating and access, plus better backstage facilities with the stage area re-built for flexibility and strength, the roof improved and insulated, the lighting grid strengthened, complete re-wiring, and technical equipment updated.

In 2013 his Headlong theatre company co-produced the premiere of Lucy Kirkwood's Chimerica, directed by Lyndsey Turner, at the Almeida: the show subsequently transferred to the West End, winning five Olivier Awards in 2014.

Almeida Projects activity includes durational residencies with partner schools, a subsidised ticket scheme for school groups visiting the theatre, productions of new plays for young people inspired by the main programme, the Young Friends of the Almeida scheme, social networking Teachers' Evenings for local performing arts teachers and a training programme for workshop leaders.