18 collection is sometimes difficult to study historically because the manuscripts no longer exist and much about them is conjecture or guesses.

He would often draw upon earlier works when looking for inspiration, keeping journals of sketches and notes.

[2] These pieces are similar in their level of intensity and stormy mood, a character which seems to be a partial product of Beethoven's use of C minor in compositions.

It begins softly, but urgently, with ostinato eighth notes in the cello, while the first violin climbs ever higher through a series of leaps.

This first subject culminates as the transition takes over in m. 13 with alternating tonic and dominant chords between the first violin and the other three instruments.

[4][2] The first movement contains one clear relationship to another piece by Beethoven, his "mit zwei obligaten Augengläsern" (Duet for a Pair of Obbligato Eyeglasses) for viola and cello.

The sforzandos placed on the 16th note of the dotted figure gives the open an almost unbalanced or off-kilter feeling.

There is a fermata in m. 12 preceded by a leap approached in contrary motion by the first violin and viola that presents itself as a question-like gesture that is then answered with a phrase similar to the opening consequent, ending on a unison C by means of a cadence.

This resolution, with its absence of a third leads to slight ambiguity in key, which is taken advantage of later in the piece.

The attempted modulation from C minor to C major is a constant source of development, only reaching its full climax in the prestissimo coda from m. 163 to the end.