In Ghent Cathedral there is a marvellous altarpiece. Among the details from it that turn up on numerous Christmas cards is an angel playing the organ. John Kitchen asks how far can a piece of iconography like this be used as the basis for instrument making.
Everyone knows the famous Flemish painting, even if only from Christmas cards of the classier sort: The One Lamp (1432) by Jan van Eyck; the original is in St Bavo’s Cathedral in Ghent. The angel musicians are playing harp and fiddle; most prominent however is a sartorially-splendid angel organist with flowing golden locks and attired in a richly decorated cloak (perhaps this is what all of us organists - at least those who get there - will look like in heaven).
Ancient, medieval and renaissance paintings feature instruments of all sorts. Since very few actual instruments have survived from before the 16th century, such iconographical evidence is vitally important in telling us what old instruments looked like, as well as in what contexts they were played, and so on. However, we must be wary of accepting such evidence too literally. There are paintings where angels are playing stringed instruments far too big to hold, where unlikely-looking bows are being held at impossible angles and the like. But on occasion we may feel that the artist really has been trying to portray things as he saw them. Van Eyck’s picture is a case in point; he may never have seen an angel, but the organ itself seems to reflect quite careful observation. Notwithstanding certain puzzling details, some commentators are convinced that here we have a pretty faithful representation of a particular instrument known to the artist. Many have written about this late-medieval instrument and several attempts have been made, based on the pictorial evidence, to reconstruct such a 'Gothic positive' organ. Dr Götz Corinth did so some years ago; his painstaking efforts are outlined in a fascinating article in the 1991 yearbook of the Incorporated Society of Organbuilders. But what is the point of doing this? What are we going to play on it? What is the angel playing on it?
Well, for a start, any early instrument (or faithful reconstruction, if such a thing is possible) offers valuable clues about performance practice issues. Here, the very short compass severely limits what you can play: the extremely short keys are bound to influence fingering-methods, and so on. A faithful-as-possible reconstruction of the Van Eyck organ would impose a number of such limitations or challenges and would thus tell us something about the performance of 15th-century keyboard music.
What medieval keyboard repertory do we have? The earliest-known is the so-called Robertsbridge Fragment, which is actually dated as early as c1320; three estampies (a kind of dance) and three intabulations of vocal music. Then there are a number of significant 15th-century German sources. But perhaps the most celebrated and extensive is the Buxheimer Orgelbuch, which seems to have been compiled about 1470. It contains over 250 sacred and secular pieces and has been available in modern editions for some time. Is the Van Eyck organ an appropriate instrument for at least some of this music? We never can be sure, but it is certainly interesting to make connections.
The music itself gives us information about compass; we can see which modes were used and thus make speculations about the temperament (would it have been Pythagorean?).
The prevailing texture of much of this music - slowish-moving lower parts with a decorated treble - might just suggest something about the scaling and voicing of the pipework. 'Scaling' means the relationship between the diameter of a pipe and its length; if this relationship is kept constant then the tone-quality will remain consistent throughout the compass. This has now been the practice for centuries, but in medieval times there is evidence that such ideas on scaling had not yet developed. Instead, they built ranks of pipes where the shortest are almost as wide as the longest. This means that the tone is stringy at the bottom, becoming more flutey as you go up the scale - and I think this might work quite well for the texture of this music. Much, however, is hypothetical.
Although much speculation and informed guesswork are bound to be involved, there are arguments in favour of attempting an accurate-as-possible reconstruction of such an organ. Neil Richerby, proprietor of Lammermuir Pipe Organs (based in Oldhamstocks near Edinburgh) has approached the matter somewhat differently. He became interested in the Van Eyck organ after having read about Dr Corinth’s work, and has now constructed two instruments based upon it, one of which I recently had the chance to inspect and play. Richerby makes no claims of authenticity, but has used the Van Eyck instrument as a starting-point for a quasi-medieval organ. Original and reconstruction look quite similar at first glance: the elegant shape, the beautiful wood-carving about the keyboard, the finish of the hammered front pipes which have a high lead content (medieval builders cast their metal in sand, giving a finish very different from the gleaming tin we are used to) - these and many other aspects of Richerby’s work are highly reminiscent of the original.
Other aspects are patently not authentic. He has increased the compass from 21 notes to four octaves, with the characteristic (17th-century) short octave arrangement in the bass. The keys are larger than the original tiny stumps, there is an 8' rank of wooden pipes (the original all seem to be of metal), and the scaling follows later practices. The necessity of providing a music desk - angels and St Cecilia seem always to have improvised - had implications for the arrangement of the front pipes whose mouths rise towards the right, wheras the originals are in a straight line. Richerby has constructed bellows behind the organ very like those in a number of medieval pictures; the player pumps these by a foot-pedal, giving a 'breathing' quality to the sound (an electric blower can be supplied for the faint-hearted). There are three ranks of pipes - 8', 4' and 2' - and, of course, no pedals.
Neil Richerby has never set out to build organs which are copies of originals. He derives inspiration from historic instruments, but uses this to develop instruments which are original to him. This organ is a reinterpretation of a medieval organ but has its own character and beauty. It is certainly appropriate for the performance of medieval keyboard music, but one can play some later music on it too. True reconstructions are invaluable, particularly in the field of harpsichords, clavichords and early pianos and many craftsmen are engaged in such work today. The case of the organ is rather more complicated, as most players expect, rightly or wrongly, to play more than one restricted area of repertory.
What are organ-builders to do? Within reason, they have to respond to the demands of players. I think that Richerby’s approach here is a valid one; a compromise, if you must, but a musical and beautiful one.