Zvklus (1959) by Karlheinz Stockhausen and Duettino Concertante (1966) by Ingolf Dahl represent two of the most significant percussion compositions that present the percussionist as soloist. The performer of these works, either unaccompanied or accompanied by a non-percussion instrument, is featured as executant, interpreter, and improvisor. They are regarded as classics in the medium of multiple percussion because of their frequency of performance and their profound effect on notation, musical composition, and the technical expectations of the percussionist. This paper examines these compositions and their historical significance to both percussion literature and the percussionist. Each of these compositions is analzyed by examining instrumentation, compositional procedures, and performance problems. Finally, the notational procedures and role of the performer in these compositions are compared. A discussion of the development of the percussion batterie, percussion ensemble, and the important early solo multiple percussion compositions provides historical perspective for these compositions. This perspective is enhanced by consideration of biography, influences, and stylistic development of each composer.