The Lost Chord is intended for all those wishing to learn how to harmonise on keyboard instruments in general and the organ in particular. For players ranging from the inexperienced amateur to the professional music student it offers an abundance of carefully graded material aimed at improving keyboard skills.

The Lost Chord commences from the assumption that the player has no experience of practical harmonisation, though he or she should be able to read and play a four-part hymn accompaniment with ease. The player who perseveres to the end of Part III will become well equipped to harmonise a wide range of melodies, to improvise simple phrases and to play from figured bass. It is for each reader to find his own point of departure in this extensive tutor.

The material in The Lost Chord does not - and indeed cannot - differ essentially from that of other publications on this subject. What does differ, is the manner in which this material is presented. Firstly, stage by stage, I have incorporated theoretical aspects into the musical material, in the hope of making the theory more meaningful by illustrating its musical effect. Secondly, the tutor increases only very gradually in difficulty, so that through the many exercises the player can gain sufficient confidence at each stage before moving on to the next. Thirdly, I have attempted to place the development of harmonic language in a historical context, and this endeavour has determined my choice of musical examples. It is therefore my belief that the present tutor compensates a number of conspicuous shortcomings in many tutors on keyboard skills.

A course on harmonisation is rather similar to a passage through the history of music, or at least a substantial part of it. The theory of harmonisation based on classical tonality can be viewed as a summary and clarification of the development of Western classical music from, say, 1600 to 1900 - now often referred to as the common practice period. Here, ‘development’ is not synonymous with progress, as if there were mention of progress from primitive to advanced music. The development of Western classical music is a story of change: changes of musical taste and expressive means, in which many social and cultural factors have played a decisive role. Changes of expressive means are reflected, for example, in the fact that a 19th-century hymn accompaniment features more types of chords than its Baroque counterpart.

The content of The Lost Chord attempts to reflect this historical process. In Part I, early hymns and chorales are harmonised only with triads in root position. In Part II, a wider range of Baroque hymns and chorales is discussed, in which the 1st inversion of the triad becomes indispensable. In Part III, we follow the course of music history with examples from the 18th and 19th centuries, in which the 2nd inversion of the triad and the chord of the 7th (and its inversions) are required, as well as experience in dealing with passing and auxiliary notes. Figured bass is a natural companion to this process, and the tutor also offers elementary exercises in improvisation.

In The Lost Chord I have aimed to clarify the necessary theory in as musical a manner as possible, in an attempt to raise it beyond a set of rules to something that may enrich our musical experience. It is for this reason that the choice and sequence of topics differ from other harmonisation tutors. Inversions of chords, for example, are not simply 'hammered in' one after the other, but are introduced and discussed in relation to their practical and musical application.

It is my sincere hope that The Lost Chord will encourage many organists, harpsichordists and pianists to challenge their creativity in harmonisation and improvisation. In so doing, we may increase our insight into the pieces we perform. Moreover, our reading ability improves as we recognise and comprehend more quickly the harmonic progressions we read and hear. But the path that must be followed is neither short nor easy, and this tutor cannot replace the invaluable help of a teacher who has already persevered along that path. Let the teacher also offer guidance in listening to relevant music, for the more one is aware of the backdrop of music history against which this tutor has been compiled, the easier it will become to place the evolution of harmony and counterpoint in its historical context.

Stephen Taylor, Utrecht (the Netherlands) 2016