A famous commercial for magnetic recording tape once asked the question: "Is it live—or Memorex"—suggesting it was impossible to tell the difference. These days, at concerts of some contemporary composers' works, the correct answer would be "It's live AND Memorex"—as there is a growing body of works that involve BOTH live performers and prerecorded tape.

A 1995 work by the American composer Ingram Marshall, titled 'Dark Waters,' was written for an English horn soloist accompanied by a prerecorded tape of fragments from old 78-rpm recordings of Jean Sibelius' chilly tone-poem "The Swan of Tuonela."

Both the live English horn part and the prerecorded tape are digitally processed and mixed at each live performance. "Those who know the Sibelius will recognize familiar strains," says Marshall. "Of course the live and taped materials are highly processed, so eventually the listener forgets about the original materials and sinks into the re-created music itself."

On today's date in 1998, Ingram Marshall and Libby Van Cleve, the English horn player for whom "Dark Waters" was written, recorded the work at St. Casimir's Church in New Haven, Connecticut.

"You can actually hear the sound of that church in the recording," recalls Van Cleve. "We finished at about 3 AM, and it was stiflingly hot—How ironic that Ingram's music—and Sibelius'—is always associated with cold climates!"

On today's date in 1829, the German composer Felix Mendelssohn was in London, participating in a gala concert to raise funds for the victims of a flood in Silesia. "Everyone who has attracted the slightest attention during the season will take part," wrote Mendelssohn. "Many offers of good performers have had to be declined, as the concert, even so, will last till the next day!"

Mendelssohn performed his Double Concerto in E Major for two pianos and orchestra, joined at the second piano by his friend and fellow-composer Ignaz Moscheles. While rehearsing for the concert, Mendessohn and Moscheles jointly prepared a special cadenza, and jokingly bet each other how long the audience would applaud it—Mendessohn predicting 10 minutes, and Mosceheles, more modestly, suggesting 5.

In the Baroque age, Double Concertos were very popular, but by Mendelssohn's day they had become less common. In our time, Concertos for Two Pianos are even rarer. One of the most successful American Double Concertos was written between 1952 and 1953 by the American composer Quincy Porter. Also known as the "Concerto Concertante," this music was commissioned by the Louisville Orchestra, and premiered by piano soloists Dorothea Adkins and Ann Monks. It proved to be one of the most popular of Porter's works, and even won the Pulitzer Prize for Music in 1954.

On today’s date in 1992, a new violin concerto by the American composer Christopher Rouse had its premiere performance in Colorado with the Aspen Music Festival Orchestra led by Leonard Slatkin and violin soloist Cho-Liang Lin, to whom the new work was dedicated.

A sense of past masters of the Violin Concerto was never far from Rouse’s mind when writing this work, as he explained in his own program notes:

“I have long been drawn to the two-movement concerto form as exemplified by Bartok's Violin Concerto, and I resolved to structure my own concerto [similarly] ... The opening movement is an elegiac barcarolle ... The second movement, a toccata, follows without pause and requires enormous virtuosity of the soloist.

“The language of the concerto is, of course, more dissonant than that found in nineteenth century counterparts ... I ... find this to be one of my more ‘objective’ compositions, lacking as it does any stated or unstated program, though I hope that ... will not lead the listener to conclude that my aim was an inexpressive one.”

These days, when "Modern Music" is on the program, a sizeable chunk of the concert hall audience might start nervously looking for the nearest exit—but that wasn't always the case.

On today's date in 1882, a 21-year old American composer and pianist named Edward MacDowell took the stage in Zurich, Switzerland, to perform his "Modern Suite" for piano at the 19th annual conference of the General Society of German Musicians, a showcase for new music whose programs were arranged by none other than Franz Liszt.

Liszt had met MacDowell earlier that year, and when MacDowell sent him the music for his "Modern Suite" for solo piano, Liszt asked the young composer to play it himself at the Society's conference in Zurich.

Now, in an era when piano virtuosos like Liszt always played from memory, MacDowell premiered his "Modern Suite" with his own manuscript score propped up in front of him at the piano. This struck contemporaries as rather odd, but MacDowell's explanation was (quote): "I had never realized that my compositions could be worth actual study or memorizing!"

The success of his First "Modern Suite" lead to the creation of a Second, and both were published a year later by the Leipzig firm of Breitkopf and Hærtel. These two suites were the first works of MacDowell to appear in print, and launched his career as one of the major American composers of the late 19th century.

On today’s date in 1919, the British composer Edward Elgar finished a work he labeled jokingly as his “Opus 1001” – a 50 second “Smoking Cantata,” intended, according to the manuscript score, as "an edifying, allegorical, improving, expostulatory, educational, persuasive, hortatory, instructive, dictatorial, magisterial, inauditory work.”

The score was completed at the Hertfordshire home of a wealthy banker named Edward Speyer, one of Elgar’s oldest friends, to whom the manuscript was given. When Elgar came to stay, Speyer had only one request, that the composer and his musician friends, “Kindly do not smoke in the hall or on the staircase.”

That’s also the full text of Elgar’s cantata.

In the middle of Elgar’s manuscript, he drew a medieval hell's mouth, belching smoke. The little score was discovered, performed, and recorded for the first time in July 2003.

On today’s date in 1982, a sci-fi movie titled “Tron” opened in theaters across the country, targeting an audience fascinated by the then still-new craze for computer gaming. In the movie, a programmer–played by Jeff Bridges–is transported from the real world into a fantastic digital universe INSIDE a computer program, where he becomes a kind of freedom fighter for the program’s oppressed and exploited components.

OK, the plot is far-fetched, but nonetheless “Tron” became a cult classic–in part because of its musical score created by Wendy Carlos, famous for her wildly successful “Switched-On Bach” album featuring Bach played on a Moog synthesizer.

Originally the idea was for Carlos to write synthesizer music for just the “computer world” scenes, and for another composer to write a conventional orchestral score for the “real world” scenes.

But Carlos convinced the producers to let her do it all, and so orchestral portions of her score were recorded in London by the London Philharmonic; the choral parts in California by the UCLA Chorus, and the synthesizer portions created in New York City by Carlos herself, with Carlos weaving all three elements into one unified and–for 1982– ground-breaking film score.

On today's date in the year 2000, amid the greenery of the Berkshires in Western Massachusetts, violinist Gil Shaham gave the outdoor, open-air premiere of this new concerto at the Tanglewood Festival. The concerto is entitled—appropriately enough—"TreeSong." Accompanying Shaham was the Boston Symphony, conducted by the concerto's composer, John Williams. Williams says this music was inspired by one particular tree in Boston's Public Garden, a kind of redwood that Botanists would identify as "metasequoia glyptostroboides," but which John Williams identified simply as "my favorite tree."

"For years," said Williams, "I loved to take walks in the Public Gardens, and I grew infatuated with this Chinese tree, the dawn redwood... It not only looked lovely, but it seemed animate, even intelligent." By chance, Williams met the retired Harvard University botanist Dr. Siu-Ying Hu, who had actually planted his favorite tree back in the late 1940's.

She told Williams the dawn redwood was thought to be extinct until 1945, when some standing forests of these trees were discovered in the western part of China, near Tibet. "When Dr. Hu came to America," says Williams, "she brought a pound of seeds and the trees have flourished here."

Curiously enough, Dr. Hu also told Williams that the dawn redwood is a survivor from the very same Jurassic era that John Williams helped to make so familiar to filmgoers via the recent series of dinosaur movies.

Unless you're a graduate student in 18th century European history, it's unlikely you know off the top of your head who the winners and losers were in the War of the Spanish Succession. Suffice it to say, on today's date in 1713, to celebrate the successful resolution of that conflict, a settlement known as the "Peace of Utrecht," this festive choral "Te Deum" was performed at St. Paul's Cathedral in London. It was written by a very ambitious 28-year old German composer named George Friedrich Handel. Handel had come to England for a 6-month visit in 1710, and then for good in the spring of 1712. We're not sure if Handel wrote his "Utrecht Te Deum" in response to an invitation from the British royal family, or wrote it "on spec" to win their favor. In any case, when performed by the Royal Musicians and the choir of the Chapel Royal on July 7, 1713, it made a tremendous impression. Handel was commissioned to provide many more festive choral and instrumental works for British monarchy in the years that followed. Handel's first royal employer was King George the First, and three years after Handel's death, King George the THIRD sat on the throne. Now, King George the Third may have suffered from madness... He may have lost the American colonies, but at least he DID know a good composer when he heard one. He idolized Handel and saw to it that the composer was buried in Westminster Abbey.

On today's date in 1971, jazz great Louis Armstrong died in New York City at the age of 69. He was born in New Orleans, and for years, all the standard reference books listed his birthday as the Fourth of July, 1900. Well, it turned out that wonderfully symbolic date was cooked up by Armstrong's manager Joe Glaser. Louis himself wasn't sure when he was born, so the 4th of July seemed as good a date as any, and was accepted as fact for many years. Eventually documents were discovered that proved Armstrong was actually born on August 4, 1901.

Armstrong earned the nickname "Satchmo"—short for "Satchelmouth"—and in later years he was affectionately dubbed "Pops." If the documentary filmmaker Ken Burns is to be believed, Armstrong was the central figure in the development of jazz in the 20th century.

In the 1960s, radical blacks criticized Armstrong as an "Uncle Tom" too eager to please white audiences, forgetting that it was Armstrong, alone among his jazz peers, who courageously criticized President Eisenhower for not defending the black children attempting to integrate Central High School in Little Rock, Arkansas.

The British music critic Norman Lebrecht offered this assessment: "Armstrong never bowed his head nor sang from anywhere but the heart. He was a figure of enormous dignity and a musical innovator of universal importance."

Acknowledging his influence in American concert music, composer Libby Larsen subtitled one of her works, a 1990 Piano Concerto, "Since Armstrong."

On today's date in 1992, lovers of the tango had good reason to be sad. The great Argentinean composer and bandoneón virtuoso Astor Piazolla had died in Buenos Aires at the age of 71.

Now, the bandoneón is a close relation of the accordion, and for his instrument Piazolla composed original music inspired by the tango, a dance form that originated in the working-class dancehalls and bordellos of Buenos Aires. While still a teen-ager, Piazolla had played bandoneón in the orchestra of Carlos Gardél, the most famous tango singer of the 1930s. Eventually, Piazolla formed his own band, which became famous throughout South America.

But Piazzola had a burning desire to write concert music, and won a scholarship to study composition in Paris with Nadia Boulanger. She encouraged him to explore the possibilities inherent in the music he knew best, and so Piazzola set about "reinventing" the tango. The result was dubbed "nuevo tango." These "new" tangos were as vital as the old ones, but often dark and brooding.

Shortly before his death, someone asked Piazolla why his music was so melancholy. "Not because I'm sad," Piazolla replied. "Not at all. I'm a happy guy. I like to taste a good wine. I like to eat well. I like to live. No, my music is sad because the tango is sad—sad and dramatic, but not pessimistic."