1. The celebration of family, not so easily come by these days, even if one of the families involved has not had the best of track records in this or any other century. I greatly appreciated the sermon by the Anglican Bishop of London. You can read it here.
2. The connections with the past. After all, a continuous, if sometimes convoluted, descent from Alfred the Great is nothing to be sneezed at. Most of us are lucky if we can trace their ancestors back a couple of hundred years or so. I can get to the last decades of the 18th century, but not beyond.
3. The music. The entrance piece "I Was Glad" by Parry is one of my all-time favorite anthems. Indeed, it is the piece I hoped to have for my own entrance, had I been fortunate enough to marry . I've been lucky enough to get to sing it twice. It is one of the greatest of those grand Anglican church pieces that the English choral tradion has produced. The rest of the music was nice too. I've always thought it is a pity that "Jerusalem" is so specifically English, as it has wonderful imagery. I especially liked the "Ubi Caritas" by Paul Mealor. The Westminster Abbey and Chapel Royal boys and men sounded great.
5. The place. Westminster Abbey is, of course, a magnificent building. But it's only partially English. Although founded as a Benedictine abbey under the last Anglo-Saxon king, Edward the Confessor, the current building was built not only by English but also by French masons brought over by King Henry III. It was added to over the centuries by subsequent kings, up till the time of the Reformation. Finally, following a building hiatus caused by the upheavals associated with: the Reformation (1533-ca. 1600), the Civil War (1641-1649), the Commonwealth (1649-1661), the Restoration (1551-1689) and the Glorious Revolution (1689), the finishing touch of the west towers was completed under George II in 1745 by Nicholas Hawksmoor. Consequently, as for so much of England's ecclesiastical patrimony, it is a Catholic building adapted to Protestant use.
I do wish their Royal Highnesses every good wish and God's blessings on their marriage.