Scope and arrangement
The Modest Altschuler scores are in published and manuscript form. Many are full orchestral scores and/or parts for music performed by the Russian Symphony Orchestra, often in early Russian editions. Some are in their original form, while others are Altschuler arrangements. The arrangements consist of entirely new scores, and modifications of the original published scores. Featured composers include Anton Arensky, Aleksandr Glazunov, Reinhold Glière, Mikhail Glinka, Alexander Ilynsky, Mikhail Ippolitov-Ivanov, Anton Rubinstein, Peter Ilich Tchaikovsky, and Sergei Vasilenko.
Some of the scores bear rehearsal and performance markings. While many are published, in certain cases the parts seem to have been copied directly from published full scores and are therefore not considered arrangements. In other cases, Altschuler credits himself on the scores as arranger. In addition to the Russian composers named above, the Altschuler arrangements contain music by Ludwig van Beethoven, Frédéric Chopin, Percy Grainger, and Joaquín Malats, among others.
Other scores in the collection are by colleagues or students of Altschuler, such as Charles Haubiel, and the composers Harlow Mills, John Powell, and Helen Howarth Wemmel. Altschuler's own music manuscripts include works for orchestra, songs, and small ensemble music meant for dancing, as well as untitled or unidentified score and part pages and sketches.
The scores are divided into Altschuler arrangements and compositions (arranged by composer and title, respectively), music by other composers, and unidentified/untitled manuscripts. Unless otherwise noted, all the scores under "music by other composers" are published.