The following compositions have been recognized, in one way or another, as being some of the most extreme examples of classical music.
Forgive me if I have left your favorite epic off the list...
16th Century English composer Thomas Tallis' Spem in Alium is scored for 8 choirs, each containing 5 distinct voices.
Representative of the best English choral music has to offer, Spem in Alium is unique in its presentation of 40 unique voices. When contrasted with a modern SATB score (soprano, alto, tenor, bass), Tallis' work presents a variegated sonic palette with which he was able to explore innumerable combinations of voices and timbres. While, initially, 40 distinct voices may sound less impressive than a full orchestral score; note that a typical, modern orchestral score calls for 30 or fewer individual parts.
In this wonderful presentation performed by the Taverner Choir, take a moment to both listen to and observe the unfolding soundscape as it ebbs and flows: from solo voice to full choir, accompanied by a kaleidoscopic representation of every voice.
Notable less for its harmonic innovation or thematic profundity and more for its sheer enormity, "The Gothic" symphony, as it's known, is recognized as being one of the longest symphonies ever written. With a performance time approaching 2 hours, it can challenge the patience and attention of even the most ardent concert patron.
Havergal Brian's massive Symphony No. 1 is the first of 32 symphonies, none of which have much impressed the modern classical zeitgeist. This is not necessarily due to a lack of charm or value inherent to his work, but rather due largely to the difficulty in programming such massive tours de force within the framework of the standard overture-concerto-symphony program so many concert bills present today.
Incorporating choral performance was nothing new at the time this symphony was written—following in the footsteps of both Beethoven and Mahler—but its inclusion lends a sense of gravity that pervades the entire second half. This 10-part recording is excruciatingly long, but comes highly recommended by this author (and he probably won’t tell if you indulge).
The moniker "Symphony of a Thousand" requires little imagination to ascertain the scope of this work. Mahler's original score leaves out no one, requiring: at least 4 parts per instrument in all the winds; a full complement of brass; additional offstage brass; full strings; 2 SATB choirs; a children's choir; a host of vocal soloists, organ and other keyboards; 2 harps; and several percussionists.
Even in reduced form, this symphony presents a challenge to the most elite orchestras, as no concert hall was designed to host this many musicians. Many organizations opt to seat choirs in balconies and build temporary stages that extend into the audience.
In a recent performance, lauded music director Gustavo Dudamel of the Los Angeles Philharmonic led a performance of over one thousand musicians to critical acclaim. View this awesome performance in two parts here:
Taken individually, any of the four operas that comprise Der Ring des Nibelungen could be considered epic, with the shortest, Das Rheingold, taking just under 3 hours to complete 4 acts with no intermission. The work performed in its entirety would take 15 hours, with no breaks. Even the most ambitious opera companies spread the performance over 4 days. To say that the demands placed on the singers, musicians, stagehands—and even the audience—are formidably onerous, does not do justice to the overwhelming difficulty of both performing and appreciating a work of this scope. That said, this prodigious composition encompasses the full range of musical expression perhaps better than any other work.
Listen to the finale of Gotterdammerung here:
In stark contrast to the previous entries, this work requires but one performer. However, the enduring influence and relevance of this work set it apart from even similarly structured compositions.
Separated into two books, written 20 years apart, this collection of 48 preludes and fugues, 2 in each major and minor key, fully encapsulates the technical mastery of J. S. Bach. His genius went unrecognized for decades after his death, and until the early 19th century, no attempts at analyzing his work were made.
The rediscovery of Bach's genius came gradually, first at the hands of critics, and later by Felix Mendelssohn, a musical genius in his own right. Recognizing the true perfection of Bach's compositions, the idea was posited to create a Bach society. After much delay, and 100 years after Bach's death, the Bach Society was founded in 1850, partly by Robert Schumann, with the goal of producing a collection of his entire catalogue. Ultimately, the 70th and final book of this collection was published in 1900. Music students today are expected to be intimately familiar with this work. It is strange, then, that 50 years of music history were practically unaware of this seminal composition.
The influence of this collection can be heard in the works of Mozart, Beethoven, Brahms, and many others considered paragons of western music. Listen to excerpts from the Well-Tempered Clavier, played here by András Schiff:
Expecting a different piece to be here? Let me know in the comments. I'm sure we would all love to have a listen!