Last year, I raved about Bloom, an iPhone app from ambient music pioneer Brian Eno. Now Eno and the team behind Bloom have created Air [app store link]. Eno says the app is like an endless version of his famous composition "Music for Airports."

Air lets users create a complex, gradually shifting composition using vocal and piano samples. There are three different listen modes - each one its own arrangement - and four different conduct modes you can use to make music by tapping different parts of the screen.

If you can get together with some friends who also have iPhones, Air can spread a composition over multiple sets of speakers. It makes sense that Eno is saying that this is how he always wanted Music for Airports to be. That piece was designed as a continually looping sound installation for use in actual airports, so a version that's infinitely variable and always changing would perfectly suit the intent of the original project. It's also starting out at a lower price point than Bloom did, costing only 2 bucks. Not too bad for infinite music!