EXHIBITIONS / Old Masters and new faces: The familiar giants are all there, but darker forces are present too at the RA's big, new show of Venetian art

THERE ARE many pleasures to be found in the Royal Academy's 'The Glory of Venice: Art in the Eighteenth Century', for after all the city was dedicated to pleasure, but the exhibition is mainly notable for its look at three artists who transcend hedonism and gaiety and whom we all ought to know better: they are Giambattista Tiepolo, Antonio Canova and Giambattista Piazzetta.

Tiepolo is familiar, but I for one keep finding new aspects in his work. Canova is of course much in the news. We won't see the Three Graces for a while yet but here is the opportunity to assess his earlier art. As for Piazzetta - what a painter] Thanks are due to the organisers for giving us more than a glimpse of a serious and unforgettable artist. The Queen owns a Piazzetta drawing and there's one unfinished and badly restored painting of his in the National Gallery.

Otherwise he's scarcely known, except to specialists. It's not often, when grown up, that one has the revelation of a new Old Master, but so it will be for many visitors to this show.

Piazzetta's personal gravity and historical position make him the anchor of the exhibition. He was born in 1682 and was an artist from childhood, so his roots are in the 17th century. A dark and baroque imagination he owed to study of Crespi and Caravaggio. His inventive drawing probably comes from that prince of draughtsmen, Guercino. Piazzetta in turn became an influence and was evidently a popular no less than a revered artist in Venice, for he is recorded in all sorts of positions in artists' professional organisations. Yet he was out of step with the mood of the new Venetian painting, and especially far from its decorative lightness. Looking for a way to describe him, one artist called him 'the Courbet of the Venetian Settecento'. It's an awkward comparison, but in the very awkwardness there's a truth.

A fine stroke in the academy's installation comes with three paintings, identically sized, that were produced for the Venetian church of St Stae in the 1720s. They are by Piazzetta, Sebastiano Ricci and the young Tiepolo, anxious to try his brush against respected older men. Therefore we could look for the styles that belong to different generations; but before these pictures one is scarcely interested in such comparisons, so gripping is Piazzetta's St James Led to Martyrdom. The dark and compressed drama of this painting has great power. And, yes, there is something Courbet-like in the lighting and stern realism that Piazzetta brings to the imaginary scene.

This combination of realism and fancy seems to run through all his work. It is especially liberated in his drawing and book illustration. On canvas it came out in a series of pastoral idylls featuring rustic characters. They are clearly plebeian but also have god-like characteristics and are engaged in activities whose purpose we cannot define. It's also difficult to pin down the atmosphere of such paintings. Eroticism is in the air, also menace. Rough people issue invitations to the spectator, yet we are beckoned towards mystery rather than knowledge. Pastoral painting, a Venetian speciality since the Renaissance, had never been quite like this before. Nor since, I think.

Obviously the RA cannot represent Venetian church fresco painting, so important a part of the city's 18th-century art, but in the magnificent Gallery V we get a sense of it. Here is Piazzetta's superb The Ecstasy of St Francis. The painter has limited himself to earth colours, as though brighter hues had never existed, but still the picture in clear and lyrical. This brown ecstasy is accompanied by Tiepolo's Immaculate Conception. The two paintings were once in the same church, so it is satisfying that they are temporarily reunited in London. Here are also a number of Tiepolo altarpieces and other religious subjects. They do not have much religious pomp. His true inspiration was in the invented worlds of allegory and mythology. He aimed for a light magnificence, and with an aim that never faltered.

Tiepolo must have been terribly clever, and his quick and graceful intelligence tends to obscure the darker and indeed devilish parts of his work. He was the heir of Veronese and made the Renaissance master's vision less dense, more aerial and buoyant. Yet Tiepolo often seems more akin to later artists. It's significant that he was the single most important influence on Goya. So we have paintings like

St James the Great Conquering the Moors, which is inherited from the Renaissance, and on the other hand a number of smaller paintings, and especially drawings, that have a modern feel, more European than Venetian.

Drawings are an important part of the exhibition and are carefully hung in rooms that also include graphics and books. I wish more sculpture had been chosen; but the works on paper are enlightening. Especially good are drawings and etchings by Marco Ricci, Antonio Guardi and Domenico Tiepolo. Giovanni Piranesi is a special case, since his art is exclusively on paper and is concerned solely with architecture, real or imagined. People do enter Piranesi's drawings, but as statuary or tiny lay-figures, playing a subsidiary role in grandiose stage sets or caught in frightening prisons. At bottom Piranesi was a reactionary artist. I found that my previous admiration for his work had evaporated in the surroundings of his contemporaries.

He lacked finesse, charm and the human dimension, matters that sing through the best high average of 18th-century Venetian painting. If the Venetian touch in those years was often too dry and sandy, the colour repetitious and figure scenes (canal scenes, too) over-

populated, we have here excellent paintings by Sebastiano Ricci, Giovanni Pellegrini, Antonio and Francesco Guardi and Bernardo Bellotto, whose landscapes I find more interesting than those of his uncle Antonio Canaletto. Bellotto looks forward to the 19th century and its interest in veracity and description. He wasn't stuck in the decorative rococo mode, which softened and then asphyxiated lesser painters.

The sculptor Antonio Canova did not die until 1822, therefore within the lifetime of one of his most eloquent detractors, the Venice- loving Ruskin. He's had a pretty bad press ever since and is regularly criticised for coldness, academicism and sentimentality. I believe him to be a good sculptor who overcomes such strictures. The Canova display in the circular front hall cannot demonstrate all his powers, but here are the dramatic Orpheus and Eurydice, originally made for a Venetian garden, the perfect little Cupid and Psyche (which is quite close in spirit to the absent Three Graces) two didactic panels and a rather stirring model for a monument to Titian.

Royal Academy, W1 (071-439 7438) to 14 Dec.

(Photograph omitted)