In 1673 Locke's treatise on music theory, Melothesia, was published. The title page describes him as "Composer in Ordinary to His Majesty, and organist of her Majesty's chapel"—those monarchs being Charles II and Catherine of Braganza. Locke also served King Charles as Composer of the Wind Music ("music for the King's sackbutts and cornets"), and Composer for the Violins. (His successor in the latter office was Henry Purcell; Locke was a family friend and may have had an influence on the young composer). In 1675 he composed the music for the score of Thomas Shadwell'sPsyche.
^Music In The Baroque Era (From Monteverdi to Bach) - Manfred F Bukofzer - Published by J.M Dent & Sons (First UK Edition 1948) - p186 "When the masque as a regular court institution fell with Cromwell's rise to power, it was an overripe and doomed form. The Commonwealth did not interrupt the musical life as severely as Burney and others have claimed. Although stage plays were forbidden, musical shows passed the censorship and music in the homes of the urban middle classes flourished more than ever. Shirley's masque Cupid and Death (1653) was privately performed with music by Christopher Gibbons and Locke."
^Henry Purcell (Glory Of His Age) by Margaret Campbell (Oxford University Press Paperback 1995) (ISBN 0-19-282368-X) p46 "...his appointment on 10 September 1677 as 'composer in ordinary with fee for the violin to his Majesty, in the place of Matthew Lock(e), deceased'...."
^Henry Purcell (Glory Of His Age) by Margaret Campbell (Oxford University Press Paperback 1995) (ISBN 0-19-282368-X) p44 "The first mention is in Pepys diary: After dinner I back to Westminster-hall...Here I met with Mr Lock(e) and Pursell, Maisters of Musique; and with them to the Coffee-house into a room next the Water by ourselfs...Here we had a variety of brave Italian and Spanish songs and a Canon for 8 Voc:, which Mr Lock(e) had newly made on these words: "Domine salvum fac Regem", an admirable thing."