Mark Morris Dance Group / English National Opera, Coliseum, LondonEarthfall, Cochrane Theatre, London

A joyous, all-singing, all-dancing celebration of life in all its hues

Motley. That's one way of describing the now 30-year-old Mark Morris Dance Group.

Though its members cut a more dancerly impression than they once did, the men still surprise with their lankiness, squatness, beards and ponytails, as unlikely to be seen in pastel Lycra as your average IT consultant. Of the women, let's just say none is likely to float away in a breeze, their chunky limbs and staid hairstyles suggesting the kind of well-behaved American girls who sign up to the Silver Ring Thing. There's something old-fashioned, too, about the way they move: earthy, earthbound, seemingly uncalculated, yet with a silken grace. The remarkable truth is that no one danced like this before Mark Morris.

That amplitude seems right for L'Allegro, il Penseroso ed il Moderato – Morris's 1988 staging of Handel's pastoral oratorio, back at the Coliseum 13 years after its first British performance there. This little-done music sets poems by Milton, juxtaposing lightheartedness – "L'Allegro" – with contemplation – "Il Penseroso". Handel got his own librettist, Charles Jennens, to write a balancing section, "Il Moderato". Together they form a picture of what, to Milton, was the known universe: the active, exterior life of fields and woods, and the bustling city; and the interior one of home, hearth and religion. And just as Handel found ingenious ways to show this abundance in music, so Morris pushes his imagination to create 30 separate, sometimes interleaved, dances, whose far-ranging moods are further enhanced by Adrienne Lobel's Rothko-esque backdrops: ever-changing slabs of delicious single colour.

At its most basic, the choreography simply pictures the score: when the music plods, skips, meanders, soars (and Handel could skip and soar for England), so do the dancers. But that's not what makes this two hours so engrossing. Morris matches Handel's and Milton's vision of the richness of life on his own terms, switching between teeming displays of formal geometry – chevrons and circles, lines and grids – and more random-looking scenes that tell human stories, so many and in such quick succession that you only ever feel you're catching half of them.

There are Milton's "populous cities" bristling with business (as well as people who merely look busy, like the dork in a pink outfit dodging the crowds and the horse dung). We see the ploughman with his (human) ox. We see couplings, the births that follow, and sleeping figures carried to dreamland. We chase with the hunt, complete with landscape in which dancers stand, twiggy-armed, as trees, shifting position to show the changing view as two foxes scamper by.

More fascinating still is Morris's ability to encompass both a literal and abstract reading at once. His response to Milton's melancholy "sweet bird" (direct precursor, surely, of Keats's nightingale), is not just to have a series of dancers mimic bird behaviour (cocking heads, preening feathers), but also to embody the music's stratospheric trills, quivering with exquisite tension like the soprano's vocal cords, visualised soundwaves, or the nerve-tingling feeling we have as we listen. At bottom, the whole piece is the result of Morris's own listening.

The pity is that even though the text is in English, and ENO's singers (directed smartly in the pit by Jane Glover) are superb, even from an expensive stalls seat you miss more than you take in of Morris's dazzling conceits. You simply don't hear enough words. The reluctance to distract from the dance with surtitles is understandable, but there has to be a better way.

At least Milton's "Come, and trip it as you go/On the light fantastic toe," came across clarion clear. In an evening that ranged from comedy butt-slapping to the most serene communing of body and spirit, it made a fitting motto.

I know not what to make of Gig, a show marking 20 years of the Cardiff-based company Earthfall. It felt as if they'd invited the wrong critic: this was a rock gig, surely, even if the band seemed barely more proficient than your average sixth-form effort. But no, dance element there was: wild, raw, outrageously sexy, utterly inebriated (though I bet the vodka they were swigging was really water) and remarkable for not tangling with the mic stands.

MMDG: Birmingham Hippodrome (0844 338 5000) 22-24 Apr

Next Week:

Jenny Gilbert runs away to the CircusFest where France's Compagnie XY takes flight