from the Guardian
http://www.guardian.co.uk/politics/2013/apr/17/margaret-thatcher-funeral-streets-procession
Thatcher chose the hymns He Who Would Valiant Be, the Charles Wesley hymn Love Divine, All Loves Excelling, reflecting the influence of her Methodist upbringing, and the patriotic verse I Vow to Thee My Country.
The organ played Psalm 84, set to the music of Johannes Brahms, which is the same piece Thatcher chose to be played at the funeral of her husband, Sir Denis Thatcher, in 2003. Thatcher's American granddaughter, Amanda, 19, read from the King James Bible, Ephesians 6, 10-18, while Cameron gave the second reading, John 14, 1-6.