This piece was premiered at the 2019 Vienna festival "Sounds Around Me", a collection of contemporary and experimental music. At the time of the premiere, 48 loudspeakers were used, and electronics containing various sounds (flapping wings, chirping, etc.) represented by astral birds were freely controlled to match the live performance of the cello, diffusing and dissipating the sounds throughout the venue. The cello and electronics reflected each other's songs, and the piece progressed as if they were having a conversation. This was a challenge to create a new form of music, in which electronics were considered as acoustic sculptures with a time axis, and birds with no substance were flown into the venue. This is the first performance in Japan for an audience. (Mukai)

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