Bernard Chasan responds to me:

>>I was startled to find an online outlet offering an apparently previously
>>unrecorded Copland work, "Billy the Kind".
>>....
>>Anyone familiar with this music?
>
>Billy the Kid was an outlaw in the old west, whose exploits became the
>subject of a ballet by Copland.  I am surprised that this is considered
>a rarity- I think that it is one of the more familiar Copland works in
>the USA.

My original intention was to extrapolate from a typing error in a database,
and to pretend that there really was a work called "Billy the Kind".
I've known and loved "Billy the Kid" for many years and own a number of
versions of it.  It and the exploits of its subject are also well-known
in this part of the world.  But my thanks to Bernard for the information.

Richard Pennycuick