Pierre Alexandre Tremblay’s fourth album for empreintes DIGITALes — do you know how many electroacoustic composers have released four albums or more on this prestigious label? You won’t need more than one hand — is a double CD set featuring five mixed works composed between 2008 and 2013. Each piece involves an instrumentalist, treatments, an interactive system, and fixed sounds. Tremblay composed for bass clarinet, piano (twice), Jean-François Laporte’s Babel table, and soprano singer Payee Chen. Each piece is complex, with many levels of meaning. The most aggressive one is Un clou, son marteau, et le béton for piano, an etude in extreme dynamics. My favorite here is Still, Again for soprano Peyee Chen, a 14-minute single-voice opera that packs a lot of punch. As for the strangest vibrations, they come from Mono no aware for Laporte, where it gets impossible to distinguish between fixed sounds, performer, and man-machine interaction.