The Three Early Pieces were written in 1894 when Schoenberg was only twenty years old. They were influenced by Brahms, who was still alive and had composed his last piano pieces, Op. 119 two years before. They were published in 1894 and most likely, Schoenberg had obtained a copy and used this latest example of the "modern" style of Brahms as a model for his own composition.

The two-piano version of the Second Chamber Symphony, Op. 38B was originally written for a chamber orchestra in early 1900 but in 1942, Schoenberg decided to write a version for two pianos. In May of that year, Leonard Stein premiered the work with Clara Silvers Steuermann playing the second piano part. The program on which the work was performed occurred during the Second World War and was called An All American Concert.

The Three Pieces, Op. 11 demonstrate a new phase of Schoenberg's composition. Composed in 1909, they were the first atonal pieces to be published. Copies of the manuscript were sent to Ferruccio Busoni with the hope of having the famous pianist perform them but he objected not only to their abandonment of traditional tonal harmony but also to their compact piano writing. Busoni wrote his own version of the second piece of the set, thus showing Schoenberg how to write a more acceptable piece by lengthening the phrases through repetition and the use of the pedals. Of course, Schoenberg objected to both aims and proclaimed that he had "invented" a new style of piano writing" in these compositions. Nevertheless, both Schoenberg's and Busoni's versions of Op. 11 No 2 were published at the same time, in 1910.

The Six Little Pieces, Op 19 illustrate Schoenberg's ability to reduce the musical elements to their very limits. Each piece has its own form, miniature though it may be, and the mood of each piece is strongly contrasting in expression. The first five pieces were written in one day, February 19, 1911; the sixth, a piece reminiscing on the death of Gustav Mahler, was composed on June 17, 1911.

Schoenberg abandoned writing miniature pieces as soon as he realized its limitations for non-tonal music. Instead, he experimented with a type of writing he later called "working with tones of a motive" in which small series of tones are developed. Thus, in the first piece of Op. 23, three notes serve as the basis for its development; in the second piece, nine notes are treated throughout as a series; in the third piece, the most difficult one, a five note figure heard at the beginning, serves as either a fugue-like subject or a cantus firmus for a set of variations. Piece No. 4 is even more unusual in that he uses three groups of triads to write a piece of great complication built around them. Finally, in Piece No. 5 he writes his first strictly twelve-tone composition, a piece he calls a Waltz.

Written at nearly the same time as Five Pieces for Piano, Op. 23 (1921-23), the Suite for Piano, Op. 25 consists of dance movements that pay homage to Bach - a Prelude, a Gavotte and Musette, a Menuett and Trio, and a Gigue - as well as an Intermezzo in the middle for lyrical contrast. This is the first opus that is strictly twelve-tone, though based on three sets of tetrachords (four notes), the third of which is Bach spelled backwards. These tetrachords are manipulated in various ways, sometimes serving as motives themselves. This work may be considered Schoenberg's neo-classical composition.

The two small Op. 33 Pieces were composed in 1929 and 1931 respectively, the latter one published in America by Henry Cowell's New Music Edition in San Francisco. Both of them use new concepts of twelve-tone writing, what may be called Invertible Hexachordal Series, in which the original six notes (hexachord) is inverted at the interval of a fifth to produce the other six notes of the twelve-tone series. This is the method Schoenberg used in all of his later works. The forms of both pieces are like traditional rondo or sonata forms.

A Schoenberg Chronicle shows the evolution of some of the most interesting music of any period. Leonard Stein wishes to pay homage to a great composer on the occasion of the fiftieth anniversary of his death. Coming full circle, Piano Spheres got its start with its opening concert on September 13, 1994, Schoenberg's 120th birthday, when Leonard played all, or nearly all, of Schoenberg's piano music.