the instrument of medium/ thawing of frozen timber

1970 recording of Jorg Demus performing Beethoven's last Piano Sonata (no. 32 in C minor, op 111) on Beethoven's 1825 Viennese Graf. [Bonn Germany]


Train, one of the 1997 recordings from the U.S. Navy Sound Surveillance System (SOSUS) network and autonomous underwater hydrophones. Possible origins of this sound are an iceberg's keel dragging along the sea floor to other vibrations generated from moving fluids, like air blowing through a clarinet, of the ocean water and the right conditions around some seamount.