Art historians can so easily get carried away looking for a thesis, a scaffolding on which to hang theories which can sometimes obscure as much as reveal. Not so here: as near perfect as might be imagined, this is a beautifully laid out, fresh look at a master painter, that lights up the National Gallery's basement exhibition space.

Sometimes you come across an artwork that changes the way you see the world. Tacita Dean’s film portrait of the American choreographer Merce Cunningham (main picture) is one such encounter.

Mortality inflects commemoration. So it is with portraiture: the likeness – particularly those which celebrate lives of status and accomplishment – will always be limned with death.

Finland is celebrating its centenary this year and the National Gallery's exhibition of four paintings by Akseli Gallen-Kalela (1865-1931) of a very large lake in central Finland is a beguiling glimpse of the passion its inhabitants attach to its scenic beauty, in winter darkness and here, summer night. Finland possesses almost 190,000 lakes, depending on your definition.

If only a modest fuss is being made about the rare and prestigious loan currently residing in Trafalgar Square, it could be that the National Gallery is keen to forget the role of its former director, Dr Nicholas Penny, in a row about art transportation that centred on the very collection to which these objects belong.

Art, design and craft is such a broad category that it is no surprise – even less a criticism – that most of the nominees comfortably inhabit just one of these areas of endeavour.

Flashes of intense colour pulse rhythmically across the piece, contrasting with delicate washes and pools of watery pigment that seem to quiver plumply, set to run uncontrollably at any moment. Lines drawn fast and bold describe four figures, while more tentative, carefully made marks barely delineate a foot, and a bird in a cage.

Michelangelo's Taddei tondo, which depicts the Madonna and Child with the Infant St John in a rocky landscape, is the only Michelangelo marble in Britain. Currently one of the stars of the National Gallery's Michelangelo & Sebastiano show, it is also one of the greatest treasures of the Royal Academy's permanent collection, and is the subject of my new book.

The story of two characters whose friendship ended in bitter enmity is juicy enough for a typical spring blockbuster and yet this is an exhibition with a serious and scholarly bent. While the National Gallery is no stranger to academic exhibitions they are usually relatively low-key, occupying the small space of the Sunley Room, for which this exhibition feels as if it might originally have been conceived.

Painted in 1891 by Tom Roberts, A Break Away! shows us a flock of maddened, thirsty sheep careering down a hillside stripped of grass by drought, accompanied by rollicking sheepdogs and cowboy shepherds on horses. If those sheep pile on top of one another into the puny stream at the bottom of the hill, injury – even death – will occur. The perspective is vertiginous, and the scene almost visibly pulsates with energy.