After presenting his spring / summer 2013 collection in Teatro Armani, his purpose-built stone and glass temple, Giorgio Armani presented an exhibition – ‘Eccentrica’ – that couldn’t have been further away from the clothes he had just shown on the runway.

Including his ‘eccentric’ creations for Lady Gaga – such as one bustier jutting spikes and apparently made of stainless steel – were incredible to see, having just witnessed Armani at his lightest, elegant best.

The runway show opened with pearl grey gossamer fine silk and organza, cut into graceful trouser suits. Trousers were the order of the day – loose, wide and cut precisely at the ankle – topped with a variety of slim jackets, long and waist-length, in contrasting hues of grey-blue.

He offered a masterclass in layering: mini jacket, over long top, over trousers. Floaty dress - waisted with fine organza scarf - over trousers. Flirtatious skirt over wispy trousers. His point: air-light trousers are a good proposition for layering under pretty much anything, for both day and evening.

The sophistication moved up a notch with navy blue – a gleaming satin tunic over, yes, you’ve guessed it, trousers – which looked utterly refined, worn with paper-flat slingbacks. And youthful too, when those satin tunics were teamed with thigh-high shorts and steep sandals with mirrored heels.

As ever, with the eveningwear, Armani pushed the decoration with embellishment in the form of beads or sequins. But the silhouettes remained constant: lean, spare and graceful. He ended with print, a constellation of stars on midnight blue – which mirrored the backdrop for his ‘Eccentrica’ exhibition next door.

It was a beautiful collection. Lady Gaga take note.

Read ELLE's exclusive interview with Giorgio Armani here..

See Lady Gaga's most iconic style moments here..