2120 South Michigan Avenue, Chicago, IL

Reader Eric asked what should be a simple question:

Do you know what song was first recorded at 2120 S. Michigan Ave. in Chicago?
I know that studio opened in the summer of '57. Could the first song have been Rock and Roll Music? It was released in Sept. 1957.

Should be easy to answer, shouldn't it? So I went through all the books I have on Chess Records to find an exact date. But none of the books tells you, when the Chess studios and office moved to this location. Spinning Blues into Gold by Nadine Cohodas is the book telling most of the story. According to Cohodas, Leonard Chess bought the property in late 1956 or early 1957. Jack Wiener, who returned to Chicago in early 1957, was given the task to build up the recording studio facilities. Chess ads used the new address in early 1957 even though the company had not yet moved in. At least during Leonard's hospitalization in Feb./March 1957 the studios were not yet functioning.
Due to this, I doubt Fred Rothwell's listing who puts Berry's January 1957 session (School Day and others) already into Twenty-One Twenty. It is more likely, though, that the following Berry session was the first located there. It took place in early May 1957, probably the 6th. This corresponds to Cohodas's saying that Leonard recorded his old team Berry, Muddy Waters, Little Walter, and Howlin' Wolf first in the new studio. All of these recorded for Chess in May and June 1957.
Supposing that the May 1957 session was the first one to take place on South Michigan Avenue, Rock And Roll Music would be the second song recorded there. That session started with Berry recording How You've Changed, a lesser known song which appeared first on the album One Dozen Berrys (Chess LP-1432) in March 1958.