How does a flute work?

The lip plate is the thin, flat piece of material attached near the end of the head joint, where the player rests their lower lip. When air is blown correctly across the embouchure hole, it causes air vibrations inside the flute through air splitting, resulting in sound/tone. The shape and material of the lip plate influence the sound quality and playability of the flute.

The head joint is sealed with a tuning cork. The crown is screwed on top of the cork and forms the visible end of the head joint. The cork itself sits inside the tube. Its position is crucial for the intonation and tuning of the flute. The crown can also be made from different metals.

Most flutes have drawn tone holes, meaning they are pulled from the tube rather than being separately soldered on. As a result, these tone holes are slightly thinner. All beginner and step-up flutes have drawn tone holes. You can easily recognize them by the slightly thicker rim at the top of the hole. If you are an advanced player or professional, you can choose between drawn or soldered tone holes. It’s a matter of testing and experimenting to find what suits you best.

Soldered tone holes are made separately and then soldered into place. Because soldered tone holes are thicker than drawn ones, they increase the flute’s weight. Players looking for a slightly darker sound and more resistance often choose a soldered tone hole model. Due to the significant time required to hand-solder each tone hole, these models are more expensive. They are typically found on flutes designed for advanced or professional players.

This means that where the tone holes meet the tube, they are beveled to allow air to flow through the instrument with less resistance and a clearer tone. It can also result in more precise tuning.

The keys cover the tone holes. Covering more tone holes lowers the pitch. Keys are attached with an arm to a rod, which is then secured to the flute’s tube with posts.

One of the first choices when selecting a flute is whether to have open or closed keys. With open keys, five keys in the middle are open: two for the left hand and three for the right hand. This means you must cover the hole completely with your fingertip; otherwise, the note won’t sound properly. The main advantage is that it encourages more precise finger placement, improving technique. Additionally, flutes with open keys tend to sound more "open" and have less resistance. Their response is often more precise and smoother than flutes with closed keys.

The advantage of closed keys is that these flutes are slightly easier to play at first, especially for children with smaller fingers. However, for flutes with open tone holes, plugs are available to cover the holes. Many flute makers now offer flutes with open keys even for beginners.

The keys cover the tone holes with pads. These are located under the key and are usually made of felt with a thin covering. Soldered tone holes require different (thinner) pads than drawn tone holes because they have a thin rim, unlike drawn tone holes.

Many handcrafted flutes for advanced players now come with a C# trill key. This is an extra key located to the left of the index finger key for the right hand. A C# trill key makes certain trills easier (such as C-C# and G3-A3) but also offers additional benefits for intonation and technique.

Keys and Trills

Just like open-hole keys, beginner flutes are increasingly offered with either a C-foot or B-foot. Compared to years ago, this now makes little difference in price. In the image, you can see a B-foot on top and a C-foot below.

Immediately before the development of the Böhm system, flutes were mostly made of wood, with an inverse conical bore and eight small tone holes that could easily be covered with the fingertips.

Böhm’s work was inspired by a flute played by soloist Charles Nicholson. This instrument had larger holes, producing a greater volume than other flutes.

In addition to large holes, Böhm introduced "full venting," meaning all keys remained open. He also aimed to place the tone holes at acoustically optimal positions on the flute’s body rather than where they were easiest for the player to cover.

To achieve this, Böhm designed a system in which the keys were mounted on a rod and connected to rings surrounding other tone holes. This allowed the closing of one hole with a finger to automatically close a second key on another tone hole.

Böhm later discovered that a larger air volume produced a stronger and more defined tone. At that point, he decided to replace the conical bore with a cylindrical one. He also found that an optimal tone was achieved when the tone holes were too large to be covered by the fingertips alone. This led him to develop a system of keys to cover the holes.

These new flutes were initially made of silver, although Böhm later produced wooden versions.

The cylindrical Böhm flute was introduced in 1847, and during the second half of the 19th century, it was gradually adopted by professional and amateur players across Europe and the rest of the world.

The Brögger Mechanism is a special system designed by Danish flute maker Johan Brögger. It replaces the traditional pins normally used in flutes.

Instead of traditional pins, the Brögger Mechanism uses a system of bridges and full back connections. This makes the mechanism smoother, quieter, and reduces wear, as there is less friction between moving parts.

In short, this system creates a more precise and durable flute that plays more comfortably and requires less maintenance.