Brahms composed three piano quartets, two of which are on this CD: Op. 25 in G-minor, composed in 1861, and Op. 60 in C-minor, partly composed in 1855 but not completed and published until 1875.
The G-minor quartet is one of Brahms' best known and most beloved chamber works. The first four notes of the opening theme dominate the first movement, especially the development section. The second movement, in 9/8 time, is a waltz-like intermezzo with a faster trio section. The third movement andante is one of Brahms' most gorgeous slow movements with an unforgettable main theme. The last movement rondo features music in the Gypsy (or perhaps more accurately Hungarian) style. This is a rousing and dynamic movement, but to me it seems to have little connection with the other movements except for the G-minor key. It could have been made a separate Gypsy fantasia, and in fact it's sometimes performed as a separate piece.
The C-minor quartet is sometimes known as the "Werther" quartet because Brahms in a colorful letter to his publisher suggested that the quartet had a program, and that it was about the well known story of a young man, Werther, for an older woman. The origin of this quartet dates to 1855, when the young Brahms is suspected of being in an unrequited love affair with Clara Schumann, so the Werther story likely had special meaning for Brahms. The two-note motif announced in the brief introduction to the allegro forms the core of the main theme and of the development section of this somber movement. The scherzo is a lively, high energy movement (without a true trio) followed by a calm and beautiful andante. The finale provides a response to the angst of the opening movement. Though not as well known as the G-minor quartet, it is every bit as splendid and represents Brahms at his best.
My preferred performances of these quartets have been those of the Beaux Arts Trio with Walter Trampler as the guest violist. I admire their precise playing as an ensemble and their careful balance between piano and strings. Though recorded in 1973, the Beaux Arts sound quality is surprisingly good. But now the Faure Quartett has recorded these works in a style similar to Beaux Arts but with even better sound, especially in their broad dynamic range. Both groups use restraint and favor clarity of expression over emotional appeal. Interestingly, I recently heard a live performance of the G-minor by the Faure Quartett that was more dramatic than the recorded one. But for a really dramatic G-minor, there's the recording by Emil Gilels at the piano along with three members of the Amadeus Quartet (recorded in 1971 and coupled with Gilels playing the Brahms Op. 10 Ballades). Gilels and the piano tend to dominate the strings, but the performance is an exciting one, especially of the Rondo alla Zingarese.