An upright single-strung harpsichord in an outer case. There is general consensus that this unusual upright harpsichord is the earliest surviving stringed keyboard instrument in the world. The instrument is neither signed nor dated and attempts to glean a date through tree-ring (dendrochronological) analysis have so far been unsuccessful. However, a fragment of a legal document used to line one of the internal joints has been dated 1470–80 and, referring to a citizen of Ulm, strongly points to a maker active in a south German-speaking city. Although Ulm is not well known as a centre of instrument making, its skilled craft workers were highly active at this time and examples of objects such as altarpieces, which utilise a variety of materials much as can be seen in this instrument, survive. The keyboard has been altered but the wide three-octave span and narrow compass – most readily understood as originally F,G to g2 with two additional pedal notes in the bass – concur with the dating of the script. Unusual features include the remains of a moulded landscape in the lower left-hand section of the case. Also, the shape of the bridge, with truncated sections branching off from the main line, perhaps represents the Tree of Life. No other harpsichord bridge is known to be carved in this fashion, but the so-called Tulip Pulpit by Hans Witten (Freiberg Cathedral, 1508–10) has a similarly carved tree trunk that supports the pulpit steps.