Trisha Brown Dance Company, Sadler's Wells, London<br></br>Josef Nadj, The Place, London

The old stuff - it's so blissfully new

What happens to radical post-modernists when they get old? Do they take up bridge and perm their hair? Do they revisit their early experiments, or do they adapt to the changing zeitgeist? The American Trisha Brown, now 67, is an adapter. As early as the late 1970s she had left behind the spare formulas of her early pieces - the walking up the sides of Manhattan buildings, the what-is-dance? enquiries. Seized by what she called "a rapture to move", she set out to create intricate compositions in which everyday movement such as walking, running, swinging an arm, blossomed into sensuous flurries of energy.

Set and Reset, made in 1983, shows her at the peak of this period, and it was good that Dance Umbrella, for this 25th birthday season, asked her to revive it. With its Robert Rauschenberg set (translucent cubes and pyramids projected with flickery newsreel) and smart Laurie Anderson score, it is very much of its time: a collage about collage, about perceiving the whole picture from tantalising scraps.

And the dance is a delight - seven bodies clad in Rauschenberg's newsprint pyjamas darting and diving and bobbing up like flotsam in a millstream. For 25 minutes the activity doesn't pause for breath, and you'd think it would be maddening with the high-pitched gong in Anderson's tape-loop banging on and on like a headache. But instead it's trance-inducing. There's no way you can watch the screens and the shapes and individual dancers all at once, so your brain finds a level of blissful inertia while all the senses spark.

The trouble with early masterpieces is that they must be followed, and neither of the two companion pieces Brown showed at Sadler's Wells made a comparable impact. Of course, it could be partly that they ask us to work harder. Geometry of Quiet, premiered last year, is a particularly uphill job, though in fact the title is an understatement. Salvatore Sciarrino's breathy score for flute and electronics registers so low on the decibel count that you think the tape must have broken.

Brown matches this barely-there quality with movement so slow and deliberating it's more like a game of chess. The geometry of the title relates to the ways bodies can slot together - a woman's head lodged in the curve of a man's neck, a woman pinioned on her partner's foot. Torsos wind into multiple knots from which single elements eventually ping free. Lengths of draped white fabric drift about, enhanced by Jennifer Tipton's sculptural lighting. But it's hard to avoid the conclusion that this time, less really is less.

The blood promised to start coursing again in Groove and Countermove, part of Brown's recent jazz trilogy. But from the start the dazzling graphic backdrop (by Terry Winters) and rainbow costumes have to fight the sapping effect of Dave Douglas's score. What is it with jazz musicians? Stop, start, grind to a halt. They no sooner hit their stride than they're noodling again.

But at least the music provided a broad canvas for Brown to show off her craft. Movement that might look random on a single body was revealed as intricately worked on two in sync. The few climactic moments yielded a memorable railway track of coloured bodies peeling off into coloured arcs, and one startling squiggling solo - furious, fluid and free. If Brown is building to another creative peak, she hasn't hit it yet. But to judge by the mood of the audience, even her duds are a treat.

Over at The Place, the Umbrella festival explored a new byway of dance with its first showing of work by Josef Nadj, more familiar to mime festival audiences. Indeed, for the first few minutes of Nadj's Le temps du repli (hard to translate, but something about the inner recesses of the heart) you wondered where dance came into it.

Nadj and his stage partner Cécile Thiéblemont do seem to be primarily actors of the Expressionist school. They spout made-up languages. They squeak and grunt and pant. They are forever changing jackets and hats. And they do love their props - chairs and tables especially. They even make origami seagulls.

But this little two-hander - three, if you count percussionist Vladimir Tarasov squeezed alongside them on stage - definitely counts as dance, if only because of the way the movement hinges on music: an eerie, improvisatory saucepan-clatter that sets up the punch lines as surely as a drum roll at the circus.

So what's it about, this heart searching? The more-or-less wordless pair are clearly husband and wife, imprisoned by their need for each other as much as by their irritation. Within the confines of their sparse kitchen, they display all the foibles of long cohabitation: boredom, petty power struggles, and fixations on the placement of household objects (there isn't much in the room but a table, but still they find things to squabble over).

The dance element is by turns comic and alarming, love-making and homicide rolled into one. The pair's stubbornness is beautifully captured. When Thiéblemont makes her body as flat as a plank, Nadj has to balance her horizontally on the furniture. When she crumples into a ball, he still doesn't know where to put her. The most lasting image, though, is lavatorial. How to keep romance alive when the expulsive act can't be private? Nadj's duet of puffs and grunts is tastefully oblique but hard-hitting.

jenny.gilbert@independent.co.uk

Dance Umbrella (www.danceumbrella.co.uk), various London venues, to 8 Nov