Alexander Mackay-Smith (1903–98) was a lawyer, author of books on equine sports, violinist and chamber musician, and music collector. He accumulated a large collection of music scores, monographs, printed library catalogs, musicological journals, bibliographies, and reference works, which he donated to the University of Virginia Music Library in 1946. The collection's strength was in contemporary editions of eighteenth-century instrumental music, particularly chamber music. It is clear from the letters that Alexander had commissioned RK to purchase items for him while he was in Paris. RK also played chamber music at Mackay-Smith's home, and it appears that Mackay-Smith and his brother, Carleton Sprague Smith, were helpful in arranging concert engagements for RK in the United States.

April 9, 1932

Dear Alexander,

The arrival of your letter yesterday produced the last of many twinges of conscience. I have been waiting to write you until I had completed your commissions at the Conservatoire and the Ste. Geneviève, which, I regret to confess, are still undone. If you are pressed, I will do them immediately, but at any rate, I shall complete them before leaving Paris. I am surprised that you have no word from Pugno. A day or so after the arrival of your last letter, I gave him the list with instructions which I believed to be perfectly clear. At any rate, I shall go down there and find out what is happening. I judge from your letter that perhaps you intended that I send it myself to you which I shall do, if it is not otherwise disposed of.

Give Miss Van Buren my greetings and convey my sentiments of envy at her new acquisition. I shall visit [Jachmann?] immediately, as I am very much interested in getting a clavichord which will be dangerous but probably possible the coming year if I can find a good one.

A great many things have happened since I last wrote you. Although several times on the point of leaving, I have remained with Landowska. I am very grateful for many phases of the technic at which I have been working with her, although it needs additional modification. I shall probably stay with her until June.