In his 90th year, Elliott Carter is doing something few nonagenarians ever do: he's premiering a striking new string quartet, his fifth. And it's an awe-inspiring piece. The Arditti String Quartet takes up the short phrases that run with and then against one another with sureness, plucking and scraping and making their bows sing. They then delve into each of the five interludes that interrogate the quartet's six sections and play through the disparate splinters of tone and flushes of midrange color as if they were perfectly logical developments. Which they're not. Carter has again brilliantly scripted a chatter of stringed voices–à la the second quartet–that converse quickly, sometimes mournfully, but never straightforwardly. This complexity of conversation is a constant for Carter, coming sharply to light in "90+" and then in Rohan de Saram and Ursula Oppens's heaving read of the 1948 Sonata for Cello and Piano, as well as in virtually all these pieces. This is a monumental recording, extending the documented work of a lamentably underappreciated American composer.

These quartets are Juilliard specialties, and anyone wanting to hear this music played with a near ideal combination of virtuosity and humanity need look no further. Carter's quartets are not for the musically faint of heart: they are uncompromisingly thorny, intricate pieces that require lots of intense, dedicated listening. Very few people doubt their seriousness–or even their claims to musical greatness–but just as few people enjoy listening to them. Perhaps this spectacular set will encourage the adventurous to give them a shot. They're worth the time.

Making her debut on Decca, Alisa Weilerstein presents three major works of the cello repertoire with Daniel Barenboim leading the Staatskapelle Berlin. The star vehicle, naturally, is Edward Elgar's Concerto in E minor, which Weilerstein plays with commanding presence, rich tone, and emotional depth. Most listeners will be drawn primarily to this performance because of the piece's familiarity, and Weilerstein's charisma and passionate playing make it the album's main attraction. Yet listeners should give Weilerstein and Barenboim credit for following the Elgar with an important if not instantly recognizable or approachable modernist work, Elliott Carter's powerful Cello Concerto. Weilerstein is quite bold to play this intensely dramatic and angular composition, and while it's unlikely to appeal to the majority of fans who adore the Elgar, it deserves its place on the program for its seriousness and extraordinary displays of solo and orchestral writing. To close, Weilerstein plays Max Bruch's Kol Nidrei, a Romantic work that returns the program to a mellow and melancholy mood and brings the CD to a satisfying close. Decca's reproduction is excellent, putting Weilerstein front and center with full resonance, but not leaving the vibrant accompaniment of the orchestra too far behind her.

Collecting five CDs for about the price of three, this set of Boulez recordings is without parallel among the conductor's new-music releases. Imagine getting Boulez's celebrated single CD of Luciano Berio's Sinfonia and Eindrücke and his equally impressive single CD of Arnold Schoenberg's Pelleas und Melisande and Variations for Orchestra, bundled with four pivotal Elliott Carter works, Sir Harrison Birtwistle's electrifying …AGM…, Gérard Grisey's Modulations, Iannis Xenakis's Jalons, Hugues Dufourt's Antiphysis, and Brian Ferneyhough's Funerailles, and you have an idea how far this set stretches.

Released between 1991 and 2005, the selections in The Warner Recordings encapsulate the period when Pierre-Laurent Aimard was signed to Erato and Teldec, performing mostly 20th-century fare and some music from the 19th century. Aimard is famous for his contributions to the modernist catalog, and his performances of works by Pierre Boulez, Elliott Carter, György Ligeti, and Olivier Messiaen are regarded as scrupulously executed and authoritatively interpreted. Aimard also recorded early 20th century pieces by Charles Ives, Alban Berg, Maurice Ravel, and Claude Debussy, as well as Romantic masterpieces of Beethoven and Liszt. A pianist's pianist, Aimard is well-rounded in his repertoire and a true master of keyboard technique, yet he has received considerably less fanfare than many of his flashier colleagues. Yet connoisseurs of piano recordings know that Aimard is indispensible, especially for his special feeling for French music, and his recordings are important documents that serious students and newcomers should appreciate.

On Soli, Tamsin Waley-Cohen's 2015 release on Signum Classics, the violinist explores modernist repertoire composed between 1944 and 2005. Because these solo violin pieces by Béla Bartók, George Benjamin, Krzysztof Penderecki, Elliott Carter, and György Kurtág are challenging for both the player and the listener, one should approach this CD with some awareness that they reflect different phases of the avant-garde movement that dominated music in the last half of the 20th century.