This remained the situation with brass instruments in the late eighteenth century (and in some places even in the twentieth). The trombone was the sole exception. Praetorius illustrated both bass and contrabass trombones in Syntagma musicum(1619). However, the latter instrument was seldom used.

Towards the end of the fifteenth century another lip-reed instrument which could play as low as the bass trombone, the bassoon and the cello had appeared. This was the serpent, invented by Edmé Guillaume of Auxerre to accompany plainchant. Its mouthpiece is inserted into a bent brass crook which in turn enters a wooden tube. In a length of some 210 cm. this tube expands from a diameter of 2 cm. to a bell of about 10 cm. Its range of two and a half octaves from C2 was ample for plainchant, the slow tempo of which gave the player time to pitch each note beforehand. The pitch of the serpent tends to be unstable owing to its wide conicity and the position of the six finger holes along its ‘S’-shaped tube which are placed conveniently for the three middle fingers of each hand, rather than in accordance with acoustic requirements. When military bands adopted the serpent in the late eighteenth century three keys were fitted, giving improved Bs, C♯s and F♯s. The serpent militaire was also more robustly constructed than the serpent d'église. At the same time, bassoon-shaped serpents appeared.