"During the United States occupation of Japan, the V-Disc collection in the Service Club at the NYK (Nihon Yusen-Kaisha) office building-barracks had several discs by various artists that carried the subtitle “Fluffs at a Record Session.” All of these contained tunes in full by the regular, famous American V-Disc artists. The fluffs records were unusual in that each contained some egregious error — usually in the lyrics — by the performer. Most of those were humorous and seemed to be intentional as is not unusual in recording sessions. The soldiers used to seek out the fluffs and play those first."
V-Disc (Wikipedia article, unattributed)