Vaslav Nijinsky spent the last years of his life in a Zurich asylum. After returning from an American tour in 1917, he retreated to Switzerland, where his wife began to notice disturbing changes in his behavior. He grew impulsive, took long walks alone, and wrote obsessively in a diary:

I am feeling through the flesh and not through the intellect. I am the flesh. I am the feeling. I am God in flesh and feeling. I am man and not God. I am simple. I need not think. I must make myself felt and understood through feeling. Scientists think about me and break their heads, but their thinking will not give any results. They are stupid. I speak simply without any tricks.

The world was made by God. Man was made by God. It is impossible for man to understand God, but God understands God. Man is part of God and therefore sometimes understands God. I am both God and man. I am good and not a beast. I am an animal with a mind. I am flesh but I do come from flesh. God made flesh. I am God. I am God. I am God. …

Finally psychiatrist Eugen Bleuler pronounced him insane. “I retired into myself,” Nijinsky said. “I retired so far that I could no longer understand people.”

[I]n music, unlike painting, there is no such thing as a forgery of a known work. There are, indeed, compositions falsely purporting to be by Haydn as there are paintings falsely purporting to be by Rembrandt; but of the London Symphony, unlike the Lucretia, there can be no forgeries. Haydn’s manuscript is no more genuine an instance of the score than is a printed copy off the press this morning, and last night’s performance no less genuine than the premiere. Copies of the score may vary in accuracy, but all accurate copies, even if forgeries of Haydn’s manuscript, are equally genuine instances of the score. Performances may vary in correctness and quality and even in ‘authenticity’ of a more esoteric kind; but all correct performances are equally genuine instances of the work. In contrast, even the most exact copies of the Rembrandt paintings are simply imitations or forgeries, not new instances, of the work. Why this difference between the two arts?

— Nelson Goodman, Languages of Art, 1968

In the early 20th century, communications between a concert manager and his artists were typically charged to the musicians. Tired of paying for lengthy telegrams and long-distance calls, violinist Mischa Elman sent this wire to his manager, collect:

AM SITTING IN THE DINING ROOM OF MY HOTEL HAVING FRENCH ONION SOUP, WHOLE WHEAT TOAST, FILET MIGNON MEDIUM RARE, MIXED SALAD WITH THOUSAND ISLAND DRESSING, FRENCH APPLE PIE A LA MODE, COFFEE WITHOUT CREAM AND SUGAR. WEATHER MARVELOUS. HAVE SPLENDID ROOM WITH MAGNIFICENT VIEW. NOW HOW DO YOU LIKE COLLECT TELEGRAMS? YOURS CORDIALLY, MISCHA ELMAN

The baby is real; the lobster and the bowl were drawn in chalk on a Hartlepool sidewalk by artist Julian Beever. Beever draws in anamorphic perspective, so his work appears distorted when viewed from most angles (below) but creates an illusion of three dimensions when seen from one privileged viewpoint.

“I expected more complaints when I posted this on my website of drawings,” he writes, “but surprisingly there have been very few. It shouldn’t be taken too seriously.”

In February 1965, Harry W. Brooks of Knoxville, Tenn., wrote to Norman Rockwell asking for the secret of his success. He received this reply:

Dear Mr. Brooks:

In reply to your letter of February 8th, I feel a little presumptive to give a formula for success, but here goes:

‘A little talent, a lot of ambition, some self-confidence and a pile of hard work.’

Sincerely yours,

Norman Rockwell

The second movement of Bruckner’s seventh symphony climaxes in a famous cymbal crash; legend has it that Bruckner added the symbolic note on hearing of Wagner’s death.

This is the only cymbal note in the whole symphony, so the player has plenty of time to worry about it.

“This note becomes the occasion of indescribable anguish to almost every cymbal player responsible for its delivery,” noted Jens Rossel of Denmark’s Århus Symphony. “It must come at precisely the right instant, or it simply ruins everything. A few minutes before, you always see the fellow begin to turn in his chair, start to rub his hands and wipe his palms on his trousers. When he stands up he plants his feet, just so, like a baseball catcher bracing himself for a fast pitch. The moment comes and the cymbals crash. It’s a matter of just a few milliseconds, but what it represents to the music is either life or death.”

But maybe that’s the essence of the job. Someone once asked Sir Malcolm Sargent, “What do you have to know to play the cymbals?” He said, “Nothing — just when.”

(Frank R. Wilson, “Music and the Neurology of Time,” Music Educators Journal 77:5, January 1991.)

Some of your old books may contain hidden artworks: Beginning in the 17th century, a book’s binder would sometimes paint a watercolor scene on the edge of the book’s page stack. If the pages were then gilded, the image might remain hidden for years until the pages were fanned.

Sometimes two different images are hidden in the same book, revealed successively when the pages are fanned “up” and “down.” In rare cases paintings are hidden not just on the book’s fore edge but on the top and bottom as well, offering a panoramic view of the painting’s subject.

John Cage’s 4’33” is commonly described as “four and a half minutes of silence,” but in fact it’s the opposite — Cage hoped to lead the audience to hear the ambient sounds of the concert hall as music, to accept as art sounds that they wouldn’t normally consider in that way.

“What they thought was silence, because they didn’t know how to listen, was full of accidental sounds,” he said of the piece’s 1952 premiere. “You could hear the wind stirring outside during the first movement. During the second, raindrops began pattering on the roof, and during the third the people themselves made all kinds of interesting sounds as they talked or walked out.”

In a broad sense 4’33” was Cage’s most significant work, but the notion of a dedicated piece of art with no substance does introduce some perplexing puzzles. The work debuted as a piano piece with a specified length, but Cage later said that “the work may be performed by any instrumentalist or combination of instrumentalists and last any length of time,” and indeed he produced varying scores in different notations. Can all of these be said to be the same piece?

The “In Futurum” movement for solo piano from Czech composer Erwin Schulhoff’s 1919 Fünf Pittoresken consists entirely of rests, but directs the performer to play “the entire song with as much expression and feeling as you like, always, right to the end!” (French pianist Philippe Bianconi wondered, “Should I just sit there?”) And Alphonse Allais’s 1897 Funeral March for the Obsequies of a Deaf Man, below, consists of 24 blank measures. Could an unwitting audience member distinguish either of these from Cage’s work?

A puzzle by philosopher Patricia Werhane of Loyola University of Chicago: Suppose that a pianist were engaged to perform 4’33” but had to withdraw at the last moment, and in desperation the stage manager sat in his place. Would this be a performance of Cage’s work? Would it be a musical performance?

Now more than 60 years old, Cage’s idea may still be too novel for a wide public. When BBC Radio 3 broadcast the first U.K. orchestral performance of 4’33” in 2004, the network had to turn off an emergency backup system that would have interpreted the silence as dead air — and begun playing music.

Swiss artist Markus Raetz created this innovative portrait of Piero della Francesca. Two mobiles are fitted with aluminum plates that are juxtaposed successively as the mobiles rotate. Piero appears between them.

Raetz’s kinetic sculpture of Kiki de Montparnasse, below, uses a similar idea: