Sonja Kraus has focused her research on broadening the cello repertoire by identifying autographs and manuscripts of unpublished cello works from the classical era.

At the moment, she is researching Franz Anton Hoffmeister. This German composer and music publisher of the 18th and early 19th century has been largely overlooked by music scholars.

As of today, no complete work list has been developed and many of his compositions exist only in autographs or manuscripts, hidden in different archives of the world. Sonja Kraus has identified three cello concertos by Hoffmeister. Currently she is in the process of creating scholarly editions of these compositions in the hope that these magnificent works find their way into the concert halls of the world.

A first version of the D major Cello Concerto edition by Franz Anton Hoffmeister was finished in Spring 2016. The first performance of this edition took place on April 14th 2016  in the Jacobs School of Music, Indiana University Bloomington. This concert was a collaboration between Sonja Kraus and the Israeli conductor Tal Samuel, conducting a student orchestra of the Jacobs School of Music. The refinement of this edition is in process and a published version is expected soon.