Back in 1989, QRS Music Center in Buffalo, NY, discovered in their
archives a master copy of an unknown ragtime piano roll, having no
label information to identify it in any way. Dan Wilke, who at the
time ran the old piano roll auction at QRS, recognized the
significance of the find and re-issued this roll for collectors,
giving it the title "Mystery Rag" and the QRS catalog number CU-527.
I recently came upon the identity of this piece by comparison with
another roll of the same tune, and thought collectors having the CU-527
recut might like to know the title. The piece is "That Tango Rag,"
composed by C. Roy Larson and published in New York City in 1914.
I don't know whether the old QRS master roll was ever commercially
issued back in the ragtime era, as this title is not listed in any
of the QRS roll information I'm aware of. If it was issued, it would
have been part of their 30,000 instrumental dance music series.