The Romantic Era is when the silver flute that we play today was originally designed. That design remains largely intact today, though of course instrument makers have made improvements to the instrument over time. Theobald Boehm is credited with the invention of our modern flute, which is why it is known as the “Boehm System” flute.
Theobald Boehm and Charles Nicholson
Theobald Boehm was a flutist, metal worker and engineer who enjoyed tinkering with flutes to allow him to perform better. He produced many wooden, conical-bore, 8-9 key flutes, as were common in the early Romantic eras. However, a performance in 1831 inspired him to rethink the flute.
Boehm heard English flutist Charles Nicholson perform in 1831. Nicholson performed on an unusual flute for the time – the embouchure and finger holes were larger than most flutes. Nicholson had large hands and could cover a larger tone hole than most flutists. He was famous for his powerful sound on the flute, and that sound inspired Boehm to revise the instrument.
I did as well as any continental flautist could have done in London in 1831, but I could not match Nicholson in power of tone, wherefore I set to work to remodel my flute. Had I not heard him, probably the Boehm flute would never have been made.Theobald Boehm
Boehm created a series of improvements in the flute, which culminated in his 1947 cylindrical bore, metal, full-keyed instrument.
Conical vs Cylindrical Bore
Many early flutes (Baroque and Classical) used a conical bore, which means that the tube of the flute tapers on one end (the foot joint diameter is smaller than the head joint diameter). The taper may be slight, but that taper improves the clarity of the upper range of the instrument – unfortunately, the low end of the instrument becomes a bit weaker.
Cylindrical bore instruments have the same diameter throughout the entire tube. This strengthens the low register and also helps to stabilize intonation. Boehm shifted the flute from conical to cylindrical.
Metal vs Wood
Thought many early flutes were wooden, the bores were constructed using a variety of materials, including ivory and metal inlays and portions of the head joint. Boehm moved to the projection capabilities over the intimate sound of wood.
The most noticeable change to Boehm’s flute is the addition of the full keywork that we are accustomed to seeing today. This change completely changed the fingering system of the flute, causing some resistance to its adoption. In the end, the advantage of the larger tone hole that can be used with a key won over the smaller holes needed to be covered by the flutist’s finger.
This change also allowed Boehm to place the tone holes at the optimal acoustic position on the flute, rather than at a location where the finger could reach. This improved the intonation and stability of his flute.