In my presentation, I will give an analytical overview of the Piano Quintet of Eduard Oja (1905–1950), a work noteworthy for at least two reasons concerning form and pitch organisation. The Piano Quintet (1935) is an example of a special type of formal design in which several formal principles, including the principle of the sonata cycle, are combined into a one-movement work. This type of formal design evolved during the first half of the 19th century and came into particular prominence in the works of Franz Liszt, Richard Strauss, and other composers of the late 19th and early 20th centuries. In my presentation, some methodological questions concerning the analysis of this formal phenomenon will be discussed. The analysis of the Piano Quintet will be preceded by reflections on two other works of Estonian chamber music–the First String Quartet (1925) of Heino Eller and the Piano Quartet (1930) of Eduard Tubin–that provided Oja with eloquent examples of this special formal principle.