Christie's King Street is showing The Meeting Ground: Scenes from the KNMA Collection until 21 August, and the unusual thing about it is the price list. There isn't one. The Kiran Nadar Museum of Art, based in Delhi, has brought part of its holdings to London for an exhibition rather than a sale, in a building that exists to move objects between owners.

Auction houses have been lending their floors to museums with increasing frequency, and the reasons are not mysterious. A saleroom in August is an expensive empty space. A museum with a collection few Londoners have seen gets a central address and an audience that already walks through the door. Both sides can call it public benefit and both sides are right, which does not make it any less a transaction of attention.

What KNMA is

The museum was founded in 2010 by Kiran Nadar, a collector who began with Indian modernists and expanded into contemporary work from South Asia and beyond. It runs on private money, it is free to enter, and it holds one of the most substantial collections of twentieth-century Indian art anywhere. A purpose-built home in Delhi is under construction.

That last fact gives this show a subtext. A collection that is preparing to open a major new building has an obvious interest in being seen abroad first, and London in August is a reasonable place to be seen.

What is on the walls

The selection runs across generations rather than movements, which is why the title talks about a meeting ground rather than a survey. The Progressive Artists' Group generation sits alongside work made in the past decade, and the argument the hang makes is about continuity, not rupture.

For a British visitor this is useful in a specific way. Indian modernism is badly under-shown here, and when it does appear it tends to be through one or two names that the market has settled on. Seeing forty works together makes the point that the story is wider than the auction results suggest.

The thing to watch

There is a version of this arrangement that serves everyone and a version that quietly turns museums into advance publicity for a market. The distinction lies in who chooses what hangs. When a collection selects its own highlights for display in a saleroom, the exhibition is also a valuation exercise, whether or not anything is for sale that week.

None of which is an argument against going. The works are real, the entry is free, and the show closes on 21 August. It is worth an hour, and it is worth noticing where you are standing while you look.