Here are some data from David Hall's Merc. chronology - US sessions only, alas: Number Label Date Initial Date Full Composer Work Artists Ensemble Conductor1 10065 Mercury 4/17/1950 1950 April 17 - 18 Fine Arts Quartet 10061 Mercury 6/27/1950 1950 June 17 - 29 Fine Arts Quartet 10062 Mercury 6/27/1950 1950 June 17 - 29 Abram Chasins, Constance Keene, piano 15032 Mercury 8/14/1950 1950 August 14 - 15 Abram Chasins, Constance Keene, piano 10070 Mercury 8/14/1950 1950 August 14 - 15 Ernest White, organ 10089 Mercury 11/28/1950 1950 November 28 - 29 & December 26 - 27 Albeneri Trio 10090 Mercury 11/28/1950 1950 November 28 - 29 & December 26 - 27 Albeneri Trio 10088 Mercury 12/28/1950 1950 December 28 Louisville Orchestra 10104 Mercury 5/25/1951 1951 May 25 - 29 SCHUBERT String Quartet No. 15 in G major, D887, op. 161 Fine Arts Quartet 10105 Mercury 5/25/1951 1951 May 25 - 29 SCHUBERT String Quartet No. 12 in C minor, D703 'Quartettsatz' Fine Arts Quartet 10107 Mercury 6/4/1951 1951 June 4 - 5 Albeneri Trio 10106 Mercury 6/4/1951 1951 June 4 - 5 Albeneri Trio 10108 Mercury 6/13/1951 1951 June 13 - 15 Roth String Quartet 10109 Mercury 6/13/1951 1951 June 13 - 15 Roth String Quartet 10110 Mercury 6/13/1951 1951 June 13 - 15 Roth String Quartet 10113 Mercury 6/30/1951 1951 June 30 - July 2 Constance Keene, piano 10133 Mercury 6/14/1952 1952 June 14 - 17 Roth String Quartet 10134 Mercury 6/14/1952 1952 June 14 - 17 Roth String Quartet 10138 Mercury 9/27/1952 1952 September 27 - 29 Constance Keene, piano