Amacher’s 1991 piece Petra was originally commissioned for the ICSM World Music Days in Boswil, Switzerland. Written for two pianos, Petra is a unique example of Amacher’s late work, a direct extension of her working methodologies for electronic compositions taken into an acoustic realm that alludes to the music of Giacinto Scelsi and Galina Ustvolskaya. The piece is a sweeping, durational work based on both Amacher’s impressions of the church at Boswil and science-fiction writer Greg Bear’s short story of the same name, in which gargoyles come to life and breed with humans in a post-apocalyptic Notre Dame.

In 2017, Blank Forms presented the American premiere of Petra in New York with Marianne Schroeder, who originally performed the piece alongside Amacher in 1991, and Stefan Tcherepnin, who performed it alongside Schroeder in 2012 at Hamburger Bahnhof, Berlin. Like much of Amacher’s work, a performance of Petra is not as straightforward as it might appear—there is no definitive score but rather a series of fragments and working notes left to be deciphered. These Philadelphia performances by Schroeder and Emily Manzo are of an expanded version based on newly discovered notes and scores from the Maryanne Amacher Archive.

An LP and CD of Marianne Schroeder and Stefan Tcherepnin’s 2017 performance of Petra is forthcoming from Blank Forms Editions. via Blankforms.org