Throughout his career he continually revised his compositions: titles were changed with an almost casual regularity (for instance, the opera "Pierrot and Pierrette" became "The Stranger", the opera-ballet "The Wizard" became "The Enchanter" and the dramatic overture for brass band "1914" became "Clive of India"), many works were assigned several different opus numbers at different times, he borrowed music from one piece to another and recast works in different forms: for example, "The Pit and the Pendulum" draws its material from the opera-ballet "The Enchanter", Symphony No.7 ("Al Aaraaf") is a transcription for string orchestra of a String Sextet, "The Masque of the Red Death" which was originally another orchestral poem became a ballet, and what was illustrative of Henry Wadsworth Longfellow's "The Skeleton in Armour" was seemingly also a close depiction of Byron's "The Corsair", whilst several different versions of his orchestral variations on "Auld Lang Syne" exist with a number of the supposed 'musical portraits' apparently applicable simultaneously to different contemporaries. Larger scores, particularly the operas in the "Cauldron of Annwn" trilogy, were also quarried to produce a variety of subsidiary works. Trios became quartets, quintets became sextets, chamber works and piano suites were augmented with additional movements only to be subsequently contracted by the removal of others, pieces for clarinet and piano were arranged for brass band and works which figure prominently in early promotional catalogues subsequently vanish from later ones: