I was glad

"I was glad" (Latin incipit, "Laetatus sum") is a choral introit which is a popular piece in the musical repertoire of the Anglican church. It is traditionally sung in the Church of England as an anthem at the Coronation of the British monarch.

The text consists of verses from Psalm 122. Numerous composers have set the words to music, among them Henry Purcell and William Boyce; its most famous setting was written in 1902 by Sir Hubert Parry, which sets only verses 1–3, 6, and 7.

The text of the anthem consists of verses from Psalm 122, from the psalter found in the 1662 Book of Common Prayer:

Most of the content of the psalm is a prayer for the peace and prosperity of Jerusalem, and its use in the coronation service clearly draws a parallel between Jerusalem and the United Kingdom, as William Blake had in his poem "And did those feet in ancient time" ("Jerusalem") (which Parry set to music in 1916).

The anthem "Laetatus sum" has been sung at the entrance of the monarch at every British coronation since that of King Charles I. Settings for earlier coronations were composed by Henry Purcell and William Boyce, among others. Thomas Attwood's setting was written for the coronation of King George IV in 1821. Parry's version was composed for the coronation of King Edward VII in 1902, and revised in 1911 for that of King George V, when the familiar introduction was added. This setting employs antiphonal choir effects and brass fanfares.

Apart from the imperial splendour of the music, the chief innovation is the incorporation in the central section of the acclamations "Vivat Rex ... " or "Vivat Regina ... " ("Long live King/Queen ...") with which the King's or Queen's Scholars of Westminster School have traditionally greeted the entrance of the monarch since the coronation of King James II in 1685. This section, which has to be rewritten every time a new monarch is crowned – because the Sovereign (and his Consort) is mentioned by name – is generally omitted when the anthem is performed on other occasions. At the coronation of a king and queen, the vivat for the queen precedes that for the king. Parry indicated in the score scope for an improvisatory fanfare between the two, should the length of the procession and timing require it: the Scholars shout their greeting as the Sovereign (and his Consort) pass through the Quire and up into the Theatre. At the last coronation, that of Elizabeth II in 1953, the acclamation took the form of "Vivat Regina Elizabetha".

The acclamation section is not sung with standard Latin pronunciation, but with a variant known as Anglicized Latin. Scholars of Classical Latin would pronounce the Vivat Regina as [ˈwiːwat reːˈɡiːna]; those of Ecclesiastical Latin would pronounce it [ˈvivat reˈdʒina]. The correct traditional English pronunciation when referring to the British monarch is /ˈvaɪvæt rɪˈdʒaɪnə/ VY-vat rih-JY-nə.

At the first performance of Parry's arrangement at the 1902 coronation, the director of music, Sir Frederick Bridge, misjudged the timing and had finished the anthem before the King had arrived, having to repeat it when the right moment came. Bridge was saved by the organist, Walter Alcock, who improvised in the interim.

Parry's setting of "I was glad" was performed on 29 April 2011 at the Westminster Abbey wedding of Prince William and Catherine Middleton as the processional music for the bride and her father and the bridal attendants. It had previously been performed at the wedding of the Duke's parents, Prince Charles and Diana Spencer in 1981.