A weekend in New York is always a challenge. The cliché, so much to do, so little time, sounds trite but that makes it no less true. I filled the recent days with visits to art exhibitions and found that along with the satisfaction that comes from looking at lovely things, the collection of people viewing the shows was itself interesting.

First on my list was the Morgan Library, a midtown jewel both in its architecture and in its holdings. Charles McKim designed J. Pierpont Morgan’s first library, in the early days of the 20th century. Over the next century, several additions were completed, the last one designed in 2006 by the Pritkzer Prize winner, architect Renzo Piano.

But it was not the building, though elegant in design, but the special exhibition of Irving Penn’s Close Encounters — Portraits of Artists and Writers that drew me to the library. For over 70 years, Penn has been a figure in photography, as both a commercial design photographer for Vogue Magazine and as a fine-art photographer — in fact, blurring the line between the two categories. Every portrait involves a triangle — the subject, the artist, and the viewer. The better known the artist, the more likely the artist’s style becomes a trigger for recognition: “Ah, it’s a Picasso.” The better known the subject, the more likely that character becomes the point of reference: “Oh, look, its Abraham Lincoln.” And the closer the image’s subject is to the viewer, the more personal the commentary: “That is my mother when she was a young girl.”

Penn loves faces and also hands. He tightly frames his subjects, letting them fill their space with energy that comes from the elegance of the pose, the rigor of the position, and the directness of the immediacy of contact between the artist and model.

This show drew an artsy crowd, in keeping with the sleek new atriums linking the many exhibition spaces. Young, hip, and knowledgeable about the personages on the wall: Willem de Kooning, Truman Capote, Louise Bourgeois, Jasper Johns (whose art work is featured uptown at a showing at the Metropolitan Museum of Art).

A walk up and over to Christie’s at Rockefeller Center featured several rooms of photographic images coming up for auction. Items for sale are rarely displayed with the same curatorial care as found in museum exhibitions but in the past several years Christie’s has given great attention to both its catalogs and preview shows, organizing the works on paper and on the walls with far more panache than previously found in such settings. One group of special viewers were the collectors, looking to purchase, not only to survey, scrutinizing the works with sets of eyes that stared at condition, provenance, and price with a focused determinism. To bid, or not to bid, that was the afternoon’s question.

Uptown, at 103rd and 5th Avenue, the Museum of the City of New York occupies a space facing Central Park. Its new director, Susan Henshaw Jones has given the institution a welcome uplift. Street Dance: The New York Photographs of Rudy Burckhardt (photographs and films) and Under New York Skies: Nocturnes by Yvonne Jacquette (paintings and pastels) anchor the first floor spaces of the building. Both are small exhibits, offering enough works to take in as a pair, especially when added to the extraordinary treat of the afternoon, a concert by the pianist Anthony Newton, playing work by Howard Swanson, R. Nathaniel Dett, Carman Moore, and Scott Joplin, all African-American composers. The performance included a premiere of a new sonata by Moore commissioned by Musica de Camara. Especially refreshing was the composition of the audience: young and older; people of color; neighbors; students of music — an eclectic appreciative crowd gathered to hear a concert, a brief respite from the random noise of the city. It was by far the most diverse group at any of the exhibitions I attended.

Last stop of the weekend gave the momentary appearance of the lightest touch, an observation quickly disproved. William Steig’s cartoons appeared in The New Yorker beginning in the 1930s, and his career was filled with books, magazine covers, cartoon, and film. His book Shrek was made into a series of animated movies by DreamWorks Animation. Love, loneliness, ambition, fear, joy, guilt — Steig drew all human emotions into his cartoons, redefining the relationship between the caption writer and the artist. Before Steig’s time at The New Yorker, cartoonists were given a caption to illustrate. Steig brought images into the magazine that then had a caption added to the illustration. The audience at this exhibition at the Jewish Museum was noisy and young, very young. Children filled the rooms, thrilled at seeing recognizable figures from books they knew well; delighted to see drawings they instinctively understood without even reading the captions. Inside the exhibition space the museum set up a “reading room” where children and books (and sometimes adult readers) were united on the floor looking through Steig’s picture books. The art on the walls and the art of the book became one.

At two out of the four shows a significant percentage of attendees were under 30 years of age — a good sign for the arts. Admission fees at most New York museum are not trivial — and the absence of fees at the major auction houses makes the viewing of upcoming sales a great and inexpensive way to see works that are usually not on public view, but in private hands. Also check the Web sites of the various institutions — almost all have a day or evening with free or reduced rates.