The collection consists of a carbon copy and a photocopy of essays entitled"O politicheskoĭ napravlennosti i soderzhanii antibolśhevistskoĭ propagandy v svi︠a︡zi s sovremennym polozheniem kresti︠́a︡n v SSSR", and "Rost khlebnogo proizvodstva v kolkhozakh stepnykh i lesostepnykh raĭonov evropeĭskoĭ chasti SSSR." There is also a brief summary, in English, of the latter essay by one Joseph A. Baclawski.

The collection contains approximately 1300 scores, half of which bear markings entered by Mikhashoff or his colleagues in preparation for performance. The collection includes manuscripts and print publications, both originals and reproductions.

The collection contains 249 cassettes featuring performances either by Mikhashoff or of his music, 801 non-commercial cassettes and 115 commercially-released cassettes that do not contain performances or works by Mikhashoff.

The collection contains 155 reel to reel tapes featuring performances either by Mikhashoff or of his music, 31 reels that do not contain performances or works by Mikhashoff, and 19 reels containing tape parts to accompany performances. Five LP sound recordings and nine compact discs are also included in the collection.

The collection contains photocopies of musical scores for 127 tangos for solo piano from 127 composers. The collection also documents the process by which Mikhashoff commissioned and performed the tangos. It includes correspondence, Mikhashoff's research into the history of the tango, and performance materials (i.e. programs and reviews). Composers commissioned for this project include Milton Babbitt, Lukas Foss, Otto Luening, Conlon Nancarrow, Luis de Pablo,and Nils Vigeland.

The collection contains thirty-one video and eight audio recordings on video cassettes, most with Yvar Mikhashoff present as performer. One video title is missing, represented only by photocopied leaves of the container.

The collection contains 423 indexed images and approximately 350 additional, un-indexed snapshots. The images include publicity shots, professional photographs and snapshots of Mikhashoff in rehearsal and performance, and snapshots from some of Mikhashoff's travels. Other people included in the images include noteworthy performers and composers, such as Aaron Copland, Virgil Thomson, Sylvano Bussotti, Henri Dutilleux, Giacinto Scelsi, Toru Takemitsu, Frederic Rzewski, Luis de Pablo, Henry Brant, John Cage, Milton Babbitt, Conlon Nancarrow, Nils Vigeland, and Poul Ruders.

The Yvar Mikhashoff Trust for New Music Records contain applications, including scores and audio/video recordings, submitted by individuals and organizations for grants from the Trust.

Family correspondence, deeds, wills, genealogical data, travel mementos, patents, clippings,and scrapbooks of Charles F. Zabriskie (CFZ) and his son Charles Lemaire Zabriskie (CLZ) of Cooperstown. Also documents of Jean LeMaire, an immigrant from France.

Two poems written by Zachary Cummings for the victims of Pan Am 103 and their friends and families