Today, many Christians - Anglicans, Catholics, Lutherans - are celebrating Trinity Sunday.
The fugue in Bach's magnificent Prelude and Fugue in E Flat Major, BWV 552, is sometimes thought of as a musical meditation on this most complex and challenging of Christian doctrines.
Here are three - of course! - performances of BWV 552: two presentations of the whole, first by an American in Florida, USA, and then by a Hungarian in the Palace of Arts, Budapest; and a presentation of the fugue only, by an Australian playing one of the great organs of the Netherlands, at St Bravo's in Haarlem.
Now, the Hungarian. And the Australian lady, playing the Fugue only.