The season is swiftly approaching its end, and this weekend marks one of the last waves of heavy concert activity before Thanksgiving rolls around again.

Two concerts this weekend offer some good off-the-beaten-path pieces of repertoire mixed in along with some core repertory, which just goes to show that if you know where to look, there are plenty of challenging listening experiences even this late in the season.

James Judd’s Knight-funded Miami Music Project has a string quartet featuring Aleksandr Zhuk and Karen Lord-Powell, violist Yael Hyken and cellist Aaron Merritt. Their program in the Arts at St. Johns series in Miami Beach includes the well-known Quartettsatz (in C minor, D. 703) of Schubert and two lesser-known works: Prokofiev’s Second Quartet (in F, Op. 92), and the String Quartet No. 1 of Erwin Schulhoff.

Schulhoff (pictured above) was one of those unfortunate composers who fell afoul of the Nazis after a brilliant early career. A member of a German Jewish family living in Prague, he was sent to a concentration camp in 1941, where he contracted tuberculosis and died the next year at age 48.

The cutting short of his career by the Nazis makes him a tragic figure, of course, but Schulhoff’s music would be worth investigating even without his history as a victim of tyranny. His earlier music, like the First String Quartet, offers a highly enjoyable take on the popular styles of the day and the traditions of the past.

It makes a good pairing with the Prokofiev quartet, which is the second of only two he wrote; the composer was much more interested in music for the theater and film, which is unfortunate because both of Prokofiev’s quartets are marvelous works full of his fine lyric gift and harmonic flavoring. The Second uses folk themes from the Kabardino-Balkaria region of Russia, and much of this quartet has a pronounced rustic scoring.

The concert is set for 3 p.m. at St. John’s on the Lake United Methodist Church on Miami Beach. Tickets are $20 at the door, but $15 online at www.artsatstjohns.com.

Later that evening, the fine American pianist Jeremy Denk performs a most challenging program when he brings the Sonata No. 1 of Charles Ives and the Goldberg Variations of J.S. Bach to the Sunday Afternoons of Music series in a special night concert.

Denk has recorded both of the Ives piano sonatas on his own label, and his performance of the better-known Concord Sonata (No. 2) at the New World Symphony a couple years back was widely praised. Few pianists have this work in their repertory because of its monumental difficulties, and the First Sonata, which is more conservative musically, is nevertheless no less innovative. Written in 1909, at the same time Schoenberg was writing his Five Pieces for Orchestra, it channels Debussy and ragtime (as well as as “Bringing in the Sheaves”) amid an edge-of-tonality texture.

It’s a difficult but beautiful work, and Denk will take no real concentration break by following that with the Goldberg Variations. Famously (if apocryphally) written to comfort an insomniac count, the Variations (BWV 988) constitute a monument to the idea of variation: Bach draws a remarkable variety of moods and styles out of the simple theme with which he began, and he makes tremendous technical demands as he does so. It’s a tour de force in every sense of the word, and it takes a pianist of unusual strong mindedness to go ahead and put both of these demanding works on one program.

Denk plays at 7:30 p.m. Sunday at Gusman Hall as a special evening performance on the Sunday Afternoons of Music series. Tickets are $35; visit www.sundaymusicals.org for more information.