"THE ESSENCE of Line: French Drawings From Ingres to Degas," an exhibition on joint display at the Baltimore Museum of Art and the Walters Art Museum (with the bulk of the BMA's art on view at the Walters and vice versa), is as if the two museums have, to borrow an image from another medium, swapped iPods for the summer. Selecting "Genre" on the click wheel and scrolling down to "19th-century French Drawing" from among their respective permanent collections, each museum has, in a sense, offered the other (not to mention the public) a taste of an idiosyncratic, yet complementary playlist.

It's an apt metaphor, especially considering that Walters Director Gary Vikan likens the collaboration between the two institutions as a "dance" of sorts.

At the Walters, most of the works on view could be classified as "working drawings," preparatory studies and sketches for other (in some cases lost, unidentified or never completed) works. At the BMA, most of the drawings are, as a rule, finished works of art in their own right. Which you prefer depends, to a large degree, less on the merits of the individual drawings than on personal taste.

None of Theodore Gericault's three 1818 sketches of the heads of naval officers, for instance, on view at the Walters -- made in preparation for Gericault's famous 1819 "Raft of the Medusa" painting, and each, in fact, a portrait of the artist -- ever made it into the completed composition. Still, the dark brown, roughly 8-by-10-inch scrap of paper and its boldly drawn faces limned in iron-gall ink are as worthy of inspection as anything in the show.

Of course, other subtleties define the halves as well. Most of the drawings owned by the Walters date roughly from the third quarter of the 19th century, the period during which William T. Walters (who, it must be remembered, was collecting the contemporary art of his day) made many of his purchases, while the strength of the BMA's collection lies in its wide range. If the works on view at the Walters, then, showcase the scope of the BMA's vaults, the BMA for its part sheds light on fine distinctions in the collecting styles and predilections of some of Baltimore's more prominent collectors, in addition to Walters: Robert Gilmor Jr.; Charles J. M. Eaton; George A. Lucas; and, of course, the well-known sisters Claribel and Etta Cone.

At the Walters, labels guide visitors to paintings certain drawings relate to (Jean-Leon Gerome's "Dutch Cavalier," e.g., excerpts the foreground figure from the artist's 1882 painting "The Tulip Folly," on display elsewhere in the museum). At the BMA, several display cases feature examples of different drawing materials and methods as a way of illuminating technique.

One thing "The Essence of Line" is not especially interested in, ironically, is the essence of line.

That's right. Contrary to what its name might suggest, the show is not a litany or deconstruction of mark-making. Sure, there's variety: from the supple, almost Gauguin-like contours of Georges Lacombe's "Studies for 'Chestnut Gatherers'" to the rough, quasi-pointillist, conte-crayon-on-paper texture of Theo Van Rysselberghe's "Evening: The Three Sethe Daughters" (hanging, wittily, near a Seurat); and from the gently luminous watercolor of Isidore-Alexandre-Auguste Pils's "Artillery Practice" to Denis-Auguste-Marie Raffet's "The Nocturnal Review," described by one critic as "not drawn with pencil, but with a pointed ray of moonlight." But it's neither an encyclopedic nor reductivist show.

Perhaps that's because what it's really celebrating, as with any instance of 'Podjacking, is the unexpected segue from one song to the next, as well as the startling mini-set. Hence the gallery at the Walters showcasing Paul Gavarni's "Twelve Months," a series of a dozen fine portraits of peasants, each one representing a month of the year, and the BMA's juxtaposition of Antoine-Louis Barye's "Large Lion" and "Python in a Tree" with Eugene Delacroix's "Lion and Snake."

In other words, it's always nice to encounter a bunch of oldies but goodies on a playlist -- Cassatt, Degas, Daumier, Ingres, Millet, Renoir, Toulouse-Lautrec, etc. -- but it's the less well-known artists -- Jules Breton, half-brothers Francois and Leon Bonvin, Alfred Dehodencq, Hector Giacomelli and many, many others -- that round out and enrich the same old songs, inviting us to hear a familiar tune or two as if for the first time.

A final note: Although "The Essence of Line" contains only about 150 drawings (only!) and the printed catalogue roughly 100 illustrated entries, images representing all 900 works from the combined collections of the Walters Art Museum and the Baltimore Museum of Art have been catalogued online in a fully searchable database at www.frenchdrawings.org. Leading some old-fashioned art lovers to wonder, perhaps: What hath the iPod wrought?

THE ESSENCE OF LINE: FRENCH DRAWINGS FROM INGRES TO DEGAS -- Through Sept. 11 at the Baltimore Museum of Art and the Walters Art Museum.

The Baltimore Museum of Art is at 10 Art Museum Dr. (at North Charles and 31st streets), Baltimore. 410-396-7100. www.artbma.org. Open Wednesday- Friday 11 to 5; first Thursday of every month until 8; Saturdays and Sundays 11 to 6. $7; seniors and college students $5; 18 and younger free; free on the first Thursday of the month.

The Walters Art Museum is at 600 N. Charles St., Baltimore. 410-547-9000. www.thewalters.org. Open Wednesday-Sunday 10 to 5; also open after hours from 5:30 to 10 on the second Friday of every month. $10; seniors $8; college students ages 18 to 25, $6; children ages 6 to 17, $2; members and children younger than 6 free; admission to the permanent collection is free on Saturdays from 10 to 1 and all day on the first Thursday of the month; admission to "The Essence of Line" is half-price at those times.

Public programs associated with the BMA exhibition include:

June 26 at 2 -- Family program: "Portraits in Pastel." Tour the BMA exhibition, then create a pastel portrait of a family member or friend. Open to ages 5 and older. Free with admission. For information, call 410-396-6321 (410-396-6001 on weekends).

Public programs associated with the Walters exhibition include:

July 10 and July 14 at 2 -- Exhibition tour. Free with admission.

July 30-31 from 1 to 4 -- Beginning drawing workshop. Instructor Michael Weiss of the Maryland Institute College of Art teaches adults ages 17 and older basic drawings skills. $85 (includes materials). Limited to 18 students. Studio B, Family Art Center.

Saturdays in July from 10 to 4 -- Drop-in art activity: "When a Line Ends, a Shape Begins." Explore a variety of drawing techniques. Free.

Degas's "Dancer." The Baltimore Museum of Art and the Walters have teamed for a joint display of drawings.Edgar Degas's "Ballet Dancer Standing" is part of "The Essence of Line."