If you go to the Museo de Bellas Artes de Bilbao as well as the new Guggenheim this autumn, you'll find an exhibition of modern British paintings borrowed from the collection of the Southampton City Art Gallery. Meanwhile, in Southampton there's a show called "Tradition and Modernity in Basque Painting 1880-1939", consisting of works from the Bilbao museum. There are long-established links, we are told, between Hampshire and Bizkaia, largely based on shipping routes; and this exchange of paintings shows Southampton's friendly interest in Basque culture. For the first time in a British gallery we see an account of a sturdy regional school of whose existence we had little idea.

The contrast is of course with painting in another northern Spanish region, Catalonia. In Britain we know a lot more about early modern Catalan art because of our fascination with Barcelona, and our natural curiosity about Picasso's formative years. A century ago, Bilbao had nothing as striking as Barcelona in the way of architecture, but there are obvious similarities between the cities. Both are the proud capitals of areas with strong separatist traditions. Both are ports, both became heavily industrialised in the 19th century, yet both have a rural hinterland in which a basically peasant economy survived until quite recent times. Artistically, these cities were just as likely to look towards Paris and northern Europe as to Madrid. And yet they did not feel provincial, being at the centre of provinces which were linguistically and culturally distinct.

On the traditional side of Basque paintings, an older, academic style is found in paintings by Juan de Barroeta y Anguisolea (1835-1906) and Ignacio Diaz Olano (1860-1937). The first gives us a rather formal landscape of Bilbao, the second a portrait in a fashionable manner of a woman playing a cello, which I guess was derived from Parisian or Roman society portraiture. This is the kind of official art you might meet anywhere in the later 19th century: it doesn't look Spanish. Obviously it did not seek a regional identity.

Soon enough, however, the Basque spirit was explored. Perhaps the crucial moment was in the foundation of the Basque Artists' Association in 1911. Then there were many depictions of peasants and village life. Two of the best of them are The Intellectuals of My Village by the deaf-anddumb Ramon de Zubiaurre Aguirrezabal and Singer Poets by his brother Valentin, also deaf and dumb. They were the sons of a composer, sad to relate, but obviously did their best to compensate for their helplessness in song and conversation by painting instead. I like Gustavo de Maeztu y Whitney's Woman with a Flower, an essay in Basque chocolate-boxism, and feel an art-historian's respect for Aurelio Arteta Errasti's Basque Country Women with Fruits and Vegetables, obviously derived from pan-European ideas of muralism and Parisian poster design. A number of pictures show this kind of influence.

It's all very instructive, but then you find yourself wondering about artists who are merely the Basque equivalents of, say, Frank Brangwyn. Their work is competent, picturesque, clearly belongs to its time, is new to British eyes - yet does not have a commanding presence. And this was surely the problem with Basque art in general. It produced no leading figure, no artist who had to be imitated or challenged, no painter who simply could not be ignored. I have no doubt that there were rivalries and disputes, as in all artistic communities, but the atmosphere of this exhibition is on the whole tranquil.

There was no major painter in Bizkaia but a host of good minor painters. I was expecting one or two eccentrics, such as often turn up in small countries when they first encounter modernism. However, eccentricity is not to be found, nor any urgent originality.

And so we look for the virtues of minor art, which are honesty, moderation, sensitivity and charm, in that order of merit, together with - in this exhibition - love of one's native soil. Take the case of Dario de Regoyos Valdes, who presents the fine little picture Good Friday in Castille, in which black and monkish people are in a religious, procession while a black and progressive locomotive steams above their heads. Valdes was an internationalist. He lived in Brussels for 11 years, often visited England, had a French wife and was a friend of Monet and Degas. His talents do not thereby belong with the general European avant-garde. He is a solid part of the middle ground of modern art, which we now find to have been well rooted in the Basque region.

A few minutes' walk from the Southampton City Art Gallery is the Millais Gallery, part of the Southampton Institute. It has been open for a year and resembles a number of other galleries belonging to the new educational establishments which have now swallowed the art schools of old. Or perhaps one should say "taken them on board", especially since the Millais Gallery's "Romancing Hollywood" is more about the ocean liners of the Thirties than the American film industry.

It's a local as well as a Hollywood show, being concerned with the way that stars used to come to London via Southampton, thus having some effect on the life of Hampshire's most cinema-struck port. On the Cunard Line's Queen Mary (maiden voyage from Southampton May 1936), her sister ship the Queen Elizabeth, on the Olympic, the Le Havre-based Normandie, the Majestic, and on the Canadian Pacific's flagship, The Empress of Britain, sailed Marlene Dietrich, Ginger Rogers, Elizabeth Taylor and Michael Wilding, Robert Mitchum, Mae West, Dorothy Lamour, Bing Crosby, Jayne Mansfield, Flanagan and Allen and many others. I mention only those whose photographs are in the exhibition. En voyage from New York, these celebrities were cared for by Southampton people who were bell-boys, waiters, cabin stewards and the like. Their reminiscences of the way that they encountered glamour are an essential part of the show and its accompanying publication (pounds 5.99).

Obviously this archive exhibition is in the Millais Gallery because it's so educational. We consider oral history, design history, film studies and so on, just as you would expect from a contemporary polytechnic-cum- university. The failure is that "Romancing Hollywood" isn't visual enough. Exhibits are in the wrong place, many photographs ought to have been enlarged, and the objects in cases are cluttered. A show about style ought itself to be stylish. It's as though the organisers of the exhibition had merely been picture researchers for the book, edited by a department head at the Southampton Institute, Anne Massey. Yet Massey hasn't quite produced a book. Professor though she be, her essay in this book is like the kind of mini-thesis produced by students on MA courses.

Southampton City Art Gallery (01703 632601), to 14 Dec; Millais Gallery (01703 319841), to 22 Nov.