The Quartettsatz follows a sonata form modified to reverse the reprise of the themes in the recapitulation. The movement opens with a restless motive in the first violin that is soon taken up in imitation by the other instruments. The premonitory mood of the main theme brightens, and is supplanted by a lyrical secondary subject suspended high in the violin’s compass. A chordal passage supported by murmurings from the cello closes the exposition. The compact development section is largely concerned with permutations of the main theme, so the recapitulation begins with the lyrical second theme, reserving the agitated opening motive for the movement’s closing gestures.

Neikrug wrote, “The Piano Quintet No. 2, commissioned by Kennedy Center, was composed in Santa Fe in 2021 for Haochen Zhang and the Dover Quartet.

“My First Piano Quintet was in one extended movement, which encompassed a somewhat traditional opening, scherzo, slow movement and finale. For the Second Quintet, I wanted to explore a completely different scenario.

“Therefore, under the title Piano Quintet No. 2, I added a subtitle: ‘In Six Parts.’ The form of the work is all about layering and perspective. This begins, on the most basic level, with the six Parts of the form. Parts I, IV and VI are the three anchors of the work. They are longer and more emotionally varied, even perhaps more profound. As a totality, they are one long, arching movement separated in time by other, shorter Parts. Over the course of the piece, this long ‘movement’ undergoes a developing exploration of several episodes of varying character. The episodic nature of this music is similar to a stream-of-consciousness. Emotions change abruptly and towards extremes rather than having preparatory transitions.

“An aside: as regards the emotional content of music, I have long left the idea of any specific, representative reflections. I believe that the emotions in music encompass their own world. Clearly, we can relate to that world and absorb the experience.

“There are several specific and recognizable aspects of these episodes found in all three Parts of this over-arching movement: a prominent three-chord progression that appears in all three Parts; longer sections that develop a flowing, chromatic melody, simpler in the strings and more embellished in the piano filigree; a falling two-chord motif; and short, plaintive, two-note cries.

“One of the most complex and difficult aspects of composing any piece is creating the last movement. A composer always faces the urge to arrive at a summation, a culmination of the previous sections. In the case of this work, Part VI becomes a natural outgrowth of its organic development from Parts I and IV.

“Parts II and III act as both small episodes on their own as well as crucial ‘spacers’ between Parts I and IV. The three anchor sections are intense and demanding of the listener. They need time in between. Part II is really an episode in sound and atmosphere, a duet for the two violins alone that are meant to sound like one instrument. It is soft, mysterious and fleeting.

“Part III, played by the piano, is in essence a chorale. It is, however, also a good example of the layering I referred to above. This specific layering manifests in softer, faster music that we hear on a different plane from the piano chorale. I think of how clouds, layered in the sky, travel at different heights and different speeds. In a further method of cohesion, the chorale stems from the three-chord motif that appears in Parts I, IV and VI.

“Part V serves the same purpose between the anchoring Parts IV and VI. It has its own sound and emotion, but also serves to separate and add space. This part is a jazzy, improvisatory, semi-unison sprint. In addition to its other functions, it also provides substantial propulsion. That accumulated energy allows for the weight of Part VI. In some ways, Part V feels like a finale and makes Part VI feel like a long coda, adding to its sense of culmination or epilogue.

“Part VI begins all pizzicato in the strings. This material is derived from the fast, secondary string parts of the Part III chorale. The music then progresses through episodes of the further-developed themes from Parts I and IV, including the chromatic melody and the three-chord theme, and ends in a calm, reflective resolution.

“Another layered aspect of the piece involves the writing for strings and piano. In many piano quintets, such as those by Brahms, Schumann and Dvořák, the piano and strings play substantially the same music. I tried to make a distinct separation, with independence for them. In much of the writing, the piano and strings can sound as if they are playing on different planes, closer or farther away.

“As with most of my music, the demands on the performers are great. The writing requires obvious mastery of their instruments, but also demands engaged emotional understanding and great ensemble. Because of the independence of the parts, each musician needs to be aware of what everyone else is playing at all times.”

The first child of the Mendelssohns’ marriage, Carl Wolfgang Paul, was born on February 7, 1838. (Felix completed the E-flat Quartet, Op. 44, No. 3 just the day before.) Cécile fell seriously ill after the delivery, however, and the following months were an anxious time for the family. By June, she had recovered sufficiently for Mendelssohn to fulfill his commitment to conduct at the Lower Rhine Festival in Cologne, but he hurried back to Leipzig, collected his growing brood (the couple had five children during the ten years of their happy marriage), and spent the summer in Berlin. It was there that he composed a setting of the Psalm 95, B-flat Cello Sonata, Andante and Presto agitato for Piano, and the D major Quartet, Op. 44, No. 1. The completed score of the Quartet was dated on July 24, 1838.

The opening movement of the D major Quartet, brilliant, virtuosic and nearly orchestral in sonority, is energized by a lusty impetuosity and rhythmic verve that seem about to burst the Classical simplicity of its sonata form. The first violin introduces the movement’s main theme, a bounding melody begun with a quickly ascending phrase that in earlier decades would have been called a “rocket motive.” The movement’s vigor slackens only briefly for the presentation of the complementary theme, a hymnal melody in a slightly sad tonality. The development section, based on the main theme, makes prominent use of the “rocket motive.” With only a brief respite to allow for the recall of the second theme, the high level of energy carries through the recapitulation to the end of the movement.

As a foil to the powerful opening Allegro, Mendelssohn placed next not the expected vivacious scherzo but a gentle Menuetto. The outer sections of the movement are lilting and graceful, while the central trio is marked by ceaseless flowing ribbons of eighth notes. The most tender sentiments of the Quartet are touched on in the bittersweet Andante. The music is disposed in sonatina form (sonata without a development section): the lyrical main theme is given by the violin above a discreet pizzicato accompaniment in the lower strings; the second theme, again initiated by the violin, employs a sustained note in the cello and an undulating counterpoint in the inner voices as background. The finale was inspired by the fiery Italian tarantella.