Noortje pointed me to Halls. Quoted from Last.fm:
Halls is the solo project of 21 year old South London musician Sam Howard.
Formed in London, UK in early 2010, Halls worked on material that would appear on the debut EP “Halls EP”, released in January 2011, which was described as having ‘ambient soundscapes buttressed by skitter-step beats.’
There is something incredibly mesmerizing about long slow harmonics in big spaceous buildings, especially when performed in a church, so here’s Halls performing in a church.