This three-CD set contains a trilogy of compositions that Radigue created using the ARP 2500 synthesizer. The first piece was completed in 1973 and premiered the following year; afterward, she devoted herself to Tibetan Buddhism and gave up music for several years. Adnos II was completed in 1980, and Adnos III premiered two years later. Each consists of a single long piece lasting approximately 72 minutes, though Adnos III is divided into four movements. All three works are ultra-minimal, consisting of synth drones that do change, really, but they do it so slowly and subtly that, especially on Adnos I, it’s like watching the sand shift on the ocean floor. Listening to it on headphones provides a radically different experience from listening through speakers; paying close attention rather than letting it play out while reading a book or walking the dog or painting your house will yield different impressions. This is as much about what you bring to it as what it gives you, but if you’re in the right mood it’s transcendent.