Mozarts's keyboards

by Christopher Nobbs

An unfinished portrait of Mozart by his brother-in-law. The painting was to depict Mozart at the piano, but only the head was completed.

It is hard now to imagine the sheer variety, the rate of change or the unfamiliarity to us of the many keyboard instruments Mozart would have met within his short but well-travelled lifetime; from the intimate travelling clavichord in his carriage to the vast quasi-orchestral organs of South Germany and Austria, from the opulent late harpsichords of London and Paris in their sunset glow to almost forgotten types such as the brilliant and agile ‘Tangentenflugel’, a relative of the early piano. And among fortepianos there was a huge variety in form and mechanism. Nor should we forget how he was open to inspiration by oddities such as the little keyboard Glockenspiel with which he teased Papageno/Schikaneder from the wings or that ghostly near-keyboard, the Glass-harmonica. Only in the recent developments of electronic keyboards can such variety be equalled and that is no parallel for the variety of physical differences in the ‘feel’ of these mechanisms.

In all instrument-building the latter half of the 18th century was an extraordinary period of innovation which sometimes went to comical extremes searching for new expressive means (perhaps Mozart came across Johann Kuhlewein’s ‘Bottle Organ’ whose keyboard controlled air blown across the mouths of tuned bottles!). But just as from the creative ferment of the mid-century’s musical forms and styles — North Germany’s Sturm und Drang, Italy’s Opera Buffa, Mannheim’s orchestral fireworks, and the mock naivety of the ‘London’ Bach, to name only a few, Mozart seems to us to have distilled a classic essence, so perhaps on a more modest level there is a parallel in the emergence of the classic Viennese-action piano, between 1770 and 1790, from another rich tumult of types and experiment.

The mechanism of a Stein piano: the key is on the right of the drawing and the escapement on the far left.

Two men, both friends of Mozart, Johann Andreas Stein (1728–92) and Anton Walter (1752–1826) are key figures in this development. In the early 1770s Stein invented a new piano action with escapement, the first major innovation in this direction since Cristofori’s initial invention at the beginning of the century (by escapement is meant an action which disconnects, at the last moment, the hammer from the impulse delivered by the key thus allowing a rapid and complete rebound from the string to the rest position). Although in weight , materials and in subtle variations of geometry there were changes, this elegant action survived in Viennese pianos for over a hundred years. Mozart wrote his famous letter of 17th October 1777 about Stein to his father: ‘...whatever way I strike the keys, the tone always remains even, never either jarring or failing to sound. It is true that a piano of this kind is not to be had for less than three hundred florins, but the pains and skill which Stein bestows on them cannot be sufficiently repaid. His instruments have a feature of their own; they are supplied with a peculiar escapement. Not one in a hundred makers attend to this; but without it, it is impossible that a piano should not buzz and jar ... The pedals, pressed by the knees, are also better made by him than by anyone else; you scarcely require to touch them to make them act and as soon as the pressure is removed not the slightest vibration is perceptible.’

A grand piano built by Hofmann with a ‘Viennese action’, similar to Walter’s.

Mozart frequently played Stein’s instruments, but around 1783 he acquired a piano by Walter, probably the one now standing in his birthplace in Salzburg. Stein seems to have been much more preoccupied by the pianissimo possibilities of his action, maintaining the clavichord as his ideal. On the other hand Walter seems to have been interested in giving the instrument greater power and to allow it to be played loudly; he introduced a ‘check’ which prevents hammers rebounding in forceful playing and began the process of strengthening the case and thickening the strings, probably prompted by the requirements of a concerto instrument. However all this is very relative — to eyes and ears accustomed to the modern concert grand, Walter’s instrument is waif-like. The total tension of the strings was a fraction of what the modern iron frame bears and you could hide several of Walter’s tiny leather-covered hammers behind one modern felted hammer-head. And, the concert over, two people could carry the slender and elegant instrument from the platform.

In Mozart’s piano writing there is no Beethovenian striving against limitations of compass or dynamic, but the use of the fortepiano should not be associated with the reduction and prettification of Mozart — his piano-writing fulfils these instruments in a match of scale to expression with a naturalness that on the modern instrument can need a constant exercise of taste and judgment to prevent bombast or coyness, or to avoid speaking in later, inappropriate, idioms of the piano’s history.