The late, great composer Maryanne Amacher is mostly known for her experiments at the sonic extremes of electronics and tape manipulation. I can still remember vividly the feeling of a sound snaking through my brainpan at will when I first heard her music. So it was with a sense of surprise and curiosity that I learned that Amacher’s “Petra” was written for twin pianos.

The 1991 composition – recorded here by Marianne Schroeder and Stefan Tcherepnin – is spacious and resonant. While it sounds initially as if more indebted to Morton Feldman, Giacinto Scelsi, or Eva-Maria Houben than the aural wizardry more commonly associated with Amacher, careful listening reveals some of the constants of Amacher’s music. Her longstanding interest in playing sonic elements off one another and her attention to space and acoustic effects are on display in this vivid performance.