Martin Heinze plays two quite different double basses: one is a remarkably small Italian 4-string bass from the 18th century. It was very likely built as a violone, as can be judged from various construction details. Lateron it was converted into a modern double bass. The second instrument was originally a 4-string double bass, constructed around 1730 in central Germany (Mitteldeutschland), and converted into a 5-string one in 1994. It originates from the area around the Dresdner Staatskapelle. An identically constructed instrument can be found in the collection of Kloster Michaelstein, close to Dresden.