in the liner notes to the 1992 double CD, Prévost writes, "Despite being (arguably) the most 'difficult' material on Matchless, The Crypt has been a mainstay for the label. It obviously pays not to underestimate the audience. Its continued success has enabled us to release other works. So we felt committed, obliged almost, to keep it available ... this music has proved itself not to be ephemeral." Composer Cornelius Cardew joined AMM in 1966, performing on piano and cello. He worked with AMM intermittently until he abandoned his earlier experimental music in the late 1970s (Cardew died in an unsolved auto accident in 1981). Composer Christian Wolff performed with AMM in 1968. Cardew and Rowe became committed to socialism and to Maoism, and thought that AMM's music should reflect their sociopolitical outlook. Prévost accuses the pair of "cultural bullying", and there was tension in the group, resulting in some AMM performances being made by alternating duos: Rowe and Cardew, Prévost and Gare. 1970s This personal and political tension culminated with a long period (about 1972 to 1976) when AMM was rarely active, and then usually as a Prévost-Gare duo. This was arguably AMM's most jazz-like era, with Gare's sputtering, squawking saxophone (unique but showing the influence of John Gilmore and Albert Ayler) brought to the fore, although Prévost has stated the music was "decidedly non-jazz." Rowe rejoined in the mid-1970s, and shortly thereafter, Gare departed, leaving a Rowe-Prévost duo for a period. 1980s and 1990s Pianist John Tilbury – previously an occasional AMM collaborator – joined in about 1980. This version of AMM generally explored quieter, more meditative sounds. Gare occasionally rejoined the group in this era; cellist Rohan de Saram was also an occasional addition. Later collaborators have included saxophonist Evan Parker and clarinetist Ian Mitchell. Christian Wolff also returned as a collaborator for a concert at the Conway Hall in London in 2001. Prévost has reported that of all their collaborators, Parker and Wolff best grasped the AMM aesthetic. 2000s The Prévost/Rowe/Tilbury line-up remained stable for two decades, only occasionally augmented by guests. In the early 1990s, the trio made their first extensive tours, with a number of well-received appearances in Europe and North America. But since about 2000, Rowe's increasing involvement with what has become known as "electroacoustic improvisation" ("eai" for short), especially under the aegis of Jon Abbey's Erstwhile Records, meant that more of his musical