By approximately 1400 the clavichord had about ten strings and inearlier examples two notes or more were produced from that string or pair of strings by making two or more tangents contact thesame string or pair of strings at different points. This typeis termed fretted, or in German Gebunden. A later type, in whicheach note has its own string, or strings, is called a "Bundfrei"clavichord. The clavichord is the simplest and usually the smallestof string keyboard instruments. It is rather like an oblong boxwith the keyboard running nearly the length of one long side andwith the horizontally placed strings almost parallel to that side.The small wrest pins and bridge are at the right-hand side andthe strings are permanently damped at their left-hand ends by astrip of felt or cloth. The strings are struck from below by smallpieces of metal shaped like a screwdriver blade, which are fixed tothe backs of the key frame as tangents.
Since about 1450 keyboards have virtually remained the same,except for a little variation in the colour of the keys, as the older ones had the reverse of the present-day key colouring. The organ was the first keyboard instrument and the weight of the keys has varied greatly since the earliest examples, whose keys were so heavy that the players were called "Organ Beaters." Around the thirteenth or fourteenth century, keyboards were laid out according to the natural modes which were the basis of the musical system. The interval of the augmented fourth, B toF, was considered discordant, so B was lowered by adding anextra short key, which procedure then led to five accidentals, B flat being followed by F sharp, E flat, C sharp, and G sharp.
Today's arrangement was found as long ago as 1361, as demonstrated by paintings of the time. The first member of the harpsichord family was the virginal or virginals. The strings on this instrument are plucked by plectra and the shape is similar to that of the clavichord. The spinet followed the clavichord and then came the more elaborate harpsichord.
Tuning often followed the meantone system where major thirdswere tuned precisely and other intervals tempered. This created somevery wild intervals and the howling sound resulted in them beingcalled "wolves" or the "wolf interval." If a series of fifths is tunedfrom the bottom A upwards, when the top A is reached it will be a quarter of a semitone sharp if all are tuned in pure intervals, and this is called the Pythagorean comma. The spinet could have received its name from a possible Italianinventor, Giovanni Spinette, or from the connection with spinethorns, which were used for plucking the strings.