No sooner had I quoted David Hockney’s censure of conceptual art than along comes an exhibition full of idea-based artworks to challenge his view.

What Hockney said of contemporary artists was, “No-one wants to simply paint a tree. That is because it’s too hard for most of them. They just want to take an idea. Painting is harder than ideas.”

Paintings of trees are currently scarce on the walls of the Circle Art Gallery in Nairobi. Instead 12 artists (just one man among them; where has all the balance gone?) have produced examples of what the gallery director Danda Jaroljmek is pleased to call “New Threads”, an investigation of “process and material”.

Boiled down, this is a celebration of the pleasures of making art, of getting stuck in and using a wide variety of materials to create something that will hopefully (in Lucien Freud’s memorable phrase), “astonish, disturb, seduce, convince”.

I cannot hope to list all the materials on show but they included paper, ink, concrete, old violin cases, paint, bronze, video (where would we be without video?) brass upholstery tacks, two old safari suits, cotton, dead flowers, cardboard, wood, raffia, wool, woven leaves and hair from cows’ tails. Sorry, I don’t know how many cows were involved or even if they gave their hair willingly or were bullied into it.

Who was this fascinating conflation of ideas and materials aimed at?

Jaroljmek told me it was targeting not the general public but other artists who, presumably, had the experience and understanding necessary to share the joy of making.

Also, with the Circle art auction on the horizon and the expectation of making a bob or two, the gallery directors felt they could use their space for something they thought important even if it did not have the commercial potential of wide public appeal.

My admiration for Hockney notwithstanding, the exhibits are by and large accessible and enjoyable — some rich and complex; others simple yet elegiac — due in large part to the care the artists took in creating them with obvious respect for their media and a tender regard for their subject matter.

This resulted in objects that can be enjoyed for themselves, with the ideas they convey as a bolt-on extra. Or indeed the other way round.

Now a few highlights from this unexpected and fascinating show.

The decorated violin cases of Souad Abdel Rassoul, called Symphony of Love, represented what she called “the melody that links life and death” and bore portraits based on the mummies found at Al Fayoum in Egypt that were painted around the time of Christ.

Inside the cases-cum-coffins were painted tendrils and leaves; plant forms denoting that in the midst of death we are in life.

Also outstanding were the four footballs of Zimbabwean sculptor Joanne Patterson Tamayo, made in bronze, concrete, old plastic bags and a reconstructed windshield, raising them to the heretic status usually reserved for the multi-million dollar heroes who kick them.

Then there was the raffia, wool and (yes!) cows’ hair hanging by Maliza Kiasuwa, which looked like an ancient Aztec headdress, opulent and royal. It represented the 2002 eruption of Nyiragongo, which engulfed the town of Goma in eastern DRC; a mystical and powerful piece with its trailing red wool being the outpouring of lava and describing the force of the volcano.

It was also beautifully balanced, the spillage of white wool onto the floor — the lava flow into Lake Kivu — forming an arc that echoed the woven raffia that, like a headdress, shows us the crater, the volcano’s mouth at the head of the hanging.

Called Nyiragongo, The Divinity Volcano, it is the star of this show.

Wambui Kamiru created a shrine with candles, prayer cards and a carpet of flowers (fresh roses added every day), while Tahir Carl Karmali used old immigration forms and pulped ID documents to create a hand-made paper matrix in delicate creams, pastel pinks and yellows which formed a deceptively quiet yet potent reference to nationality, authenticity and belonging.

So has Hockney, himself a great innovator, got it wrong?

No, of course not. Many contemporary artists find good painting too hard. The evidence is on most gallery walls. And there were several exhibits at the Circle that I thought sloppy and at best an easy hit.

But that should not diminish the fact that conceptual art by accomplished artists like many in this show can surprise, delight and lift our spirits.

The discussion should focus not so much on the chosen discipline, but on the quality of the finished work.