A collaboration of Ryuichi Sakamoto and Christian Fennesz. Begun in Rome when they performed a laptop duet at the Auditorium Della Parco Musica for the Romaeuropa Festival on November 28, 2004. The 19 minute overture was recorded and released as the Sala Santa Cecilia EP by Touch in 2005.

They worked together on their debut album during 2004–2006, Sakamoto in New York and Fennesz in Vienna. They would exchange guitar, piano and electronic pieces, share notes and ideas, develop themes together. Periodically, two artists would meet for a live performance. Eventually Sakamoto and Fennesz sat in NYC to make a final mix.

Sakamoto composed 24 tracks for their second album Flumina whilst touring Japan. At the beginning of every show he played a piano piece in a different key, ending up with 24 recordings covering all tonal steps of the western tonal system. Fennesz processed and modified these tracks with synthesizers, guitar and electronics, until they again met to finalize the double album at KAB Studios in New York.