"Suze (The Cough Song)" is the early form of "Nashville Skyline Rag." The song was recorded on October 24, 1963, but wasn't formally released until March 26, 1991, on The Bootleg Series Volumes 1–3: Rare & Unreleased, 1961–1991. It's the first known instrumental recording that Dylan ever made.
The song was interrupted by a fit of coughing by Dylan, which forced producer Tom Wilson to stop the recording, thus the title.
The song appears to have been an early sketch of something intended to be on The Times They Are A-Changin', but it didn't get put on that album or any other until it was released on the Bootleg Series many years later. It did, however, mutate into "Nashville Skyline Rag" and find a home on Nashville Skyline album.