The precise details regarding the composition of this work are unknown. The critical edition published by Muzgiz and Jurgenson in 2011 dates it to 1891, while The New Grove Dictionary of Music and Musicians (2nd edition) states 1892; however, the sources for both dates are unclear. 

Nevertheless, it is certain that the work was composed earlier, as the autograph manuscript was sent to the publisher Jurgenson in December 1893, when Scriabin was 21 years old, along with the second and third pieces of Three Pieces, Op. 3. The work was eventually published in 1895, two years after the manuscript was sent. 

On the "Mazurka" style "Impromptu"

What characteristics of this piece led to its eclectic title, "Mazurka" style "Impromptu"? Firstly, examining the melody of the main section in No. 1, where the second beat is slightly prolonged and emphasized, and similarly the melody of No. 2, which also features an accent on the second beat, it is undeniable that these sections are in a "mazurka" style. 

Despite possessing such characteristics, the reason these two pieces are titled "Mazurka style Impromptu" rather than simply "Mazurka" can be found in their musical structure. The term "Impromptu" immediately brings to mind those by Schubert and Chopin. Their "Impromptus" generally possess an A-B-A arch-like structure. Pieces with such a structure often feature contrasting characters between sections A and B. For example, Chopin's Fantaisie-Impromptu consists of a virtuosic A section and a lyrical B section. These pieces by Scriabin, similar to their "Impromptus," also have an arch structure comprising A and B sections, with a clear contrast between the two. Specifically, this means a "mazurka-like" A section, as mentioned, and a non-mazurka-like B section. It is from these formal characteristics that the work is believed to bear its eclectic title. 

No. 1: G-sharp minor

The aforementioned "contrast" is established between the mazurka-like, dance-like character of the A section and the fickle or meditative character of the B section in B major. The harmony throughout is colorful, with frequent chromatic progressions. 

No. 2: F-sharp major

This piece also features a mazurka-like A section, but unlike No. 1, it is contrasted with a more rhythmic B section. The harmonic treatment here is arguably more sophisticated than in No. 1; the bass line, starting from a single note at the beginning, is also primarily chromatic and colorful, and a complete resolution to the tonic of F-sharp major does not occur until measure 32. The rhythm also employs a more complex notation compared to No. 1, with the appearance of quadruplets, septuplets, and octuplets at the end of the A section, and syncopation in the B section.