Suite for three clarinets (E♭, B♭, and bass), violin, viola, violoncello and piano, Op. 29 (1925) (with ossia flute and bassoon parts substituting for E♭ and bass clarinet)
Sonata for violin and piano (1927) (a 43-bar fragment)
Suite for Strings in G Major in five movements (1934)
Fanfare on motifs of Die Gurre-Lieder (11 brass instruments and percussion) (1945)
String Trio, Op. 45 (1946)
Phantasy for violin and piano, Op. 47 (1949)
Keyboard
Drei Klavierstücke [3 Pieces] (1894)
6 Stücke [6 Pieces] for 4 hands (1896)
Scherzo (Gesamtausgabe fragment 1) (ca. 1894)
Leicht, mit einiger Unruhe [Lightly with some restlessness], C♯ minor (Gesamtausgabe fragment 2) (ca. 1900)
Langsam [Slowly], A♭ major (Gesamtausgabe fragment 3) (1900/01)
Wenig bewegt, sehr zart [Calmly, very gentle], B♭ major (Gesamtausgabe fragment 4) (1905/06)
"Petrarch-Sonnet" from Serenade, Op. 24 (1920/23) (bass with 7 instruments)
4 Deutsche Volkslieder [4 German folksongs] (1929)
Ode to Napoleon Buonaparte for voice, piano and string quartet, Op. 41 (1942). Based on Lord Byron's poem of the same name.
3 Songs, Op. 48 (1933)
Canons
O daß der Sinnen doch so viele sind! [Oh, the senses are too numerous!] (Bärenreiter I) (April? 1905) (4 voices)
Wenn der schwer Gedrückte klagt [When the sore oppressed complains] (Bärenreiter II) (April? 1905) (4 voices)
Wer mit der Welt laufen will [He who wants to run with the world] (for David Bach) (Bärenreiter XXI) (March 1926; July 1934) (3 voices)
Canon (Bärenreiter IV) (April 1926) (4 voices)
Von meinen Steinen [From my stones] (for Erwin Stein) (Bärenreiter V) (December 1926) (4 voices)
Arnold Schönberg beglückwünschst herzlichst Concert Gebouw [Arnold Schoenberg congratulates the Concert Gebouw affectionately] (Bärenreiter VI) (March 1928) (5 voices)
Mirror canon with two free middle voices, A major (Bärenreiter VIII) (April 1931) (4 voices)
Jedem geht es so [No man can escape] (for Carl Engel) (Bärenreiter XIII) (April 1933; text 1943) (3 voices)
Mir auch ist es so ergangen [I, too, was not better off] (for Carl Engel) (Bärenreiter XIV) (April 1933; text 1943) (3 voices)
Perpetual canon, A minor (Bärenreiter XV) (1933) (4 voices)
Mirror canon, A minor (Bärenreiter XVI) (1933) (4 voices)
Es ist zu dumm [It is too dumb] (for Rudolph Ganz) (Bärenreiter XXII) (September 1934) (4 voices)
Man mag über Schönberg denken, wie man will [One might think about Schoenberg any way one wants to] (for Charlotte Dieterle) (Bärenreiter XXIII) (1935) (4 voices)
Double canon (Bärenreiter XXV) (1938) (4 voices)
Mr. Saunders I owe you thanks (for Richard Drake Saunders) (Bärenreiter XXVI) (December 1939) (4 voices)
I am almost sure, when your nurse will change your diapers (for Artur Rodzinsky on the birth of his son Richard) (Bärenreiter XXVIII) (March 1945) (4 voices)
Canon for Thomas Mann on his 70th birthday (Bärenreiter XXIX) (June 1945) (2 violins, viola, violoncello)
Gravitationszentrum eigenen Sonnensystems [You are the center of gravity of your own solar system] (Bärenreiter XXX) (August 1949) (4 voices)
Mahler: Das Lied von der Erde [The Song of the Earth] (arr. Arnold Schoenberg & Anton Webern, 1921; completed by Rainer Riehn, 1983: soprano, flute & piccolo, oboe & English horn, clarinet, bassoon & contrabassoon, horn, harmonium, piano, 2 violins, viola, violoncello, double bass)
Mahler: Lieder eines fahrenden Gesellen [Songs of a Wayfarer] (arr. 1920: voice, flute, clarinet, harmonium, piano, 2 violins, viola, violoncello, double bass, percussion)
Monn: Concerto for cello in G minor, transcribed and adapted from Monn's Concerto for harpsichord (1932/33)
Max Reger: Eine romantische Suite [A Romantic Suite], Op. 125 (arr. Arnold Schoenberg & Rudolf Kolisch, 1919/1920: flute, clarinet, 2 violins, viola, violoncello, harmonium for 4 hands, piano for 4 hands)