That's what it was purported to be, but it has since been established that the recording in question was made over a year earlier. 7th June 1955 is the latest word, if I remember correctly. It could not have been from the night Brownie died, as previously was claimed, since Billy Root was on tour with Stan Kenton then. Brownie did play at the same location just hours before he died, but that occasion seems to have gone unrecorded.