Closer Look at the C# Trill

Often times, we have customers ask if a C# trill can be added to their flute as an aftermarket customization.  It can get pretty tricky since this type of customization would require an extra tone hole to be put in the flute -- which changes the body, which can change the response and sound, and...  Well, the list goes on.  It's more complicated that just adding a key.  So, we began wondering about other differences between flutes with and without a C# trill key.  We stopped by flute finisher Karl Kornfeld's bench just as he was working on a Powell Conservatory with a C# trill.

We took a series of photos which you will see below to illustrate the differences.  Flutes with a C# trill are very easy to identify -- you can clearly see the C# trill key next to the Bb shake.  If you look a little more closely, you'll begin to notice a few more additions to make the C# trill function properly.  Beginning with the back of the flute, you will notice an extra tone hole (and key cup) next to the thumb keys.  Looking at the front of the flute, you can see a couple of additions to the mechanism.  First, the C# trill key requires an extra mechanism tube.  This extra tubing needs to be stabilized so that it does not bend -- so, there is an extra cradle for the tube.  There is also an extension on the post at the end of the tube, which is actually one piece.  Finally, because there is an extra key on the flute, the key requires an extra adjustment for key height.

So, as we can see, the C# trill adds more than just a little key to the mix.  Obviously, the tone hole for the key is made along with all the other tone holes during the body fabrication process.  As noted above, flutes with a C# trill require several additional parts for the mechanism.  If you have a C# trill key on your flute, or if you are looking at flutes with a C# trill, take a closer look -- you'll see more than just a key!

One thing you'll notice right away is the extra tone hole next to the thumb keys.

A closer look at the extra tone hole. 

The actual C# trill key is easy to spot.

Yellow and orange arrows point to the mechanism tubing that both flutes have -- blue arrow points to the extra tube for the C# trill key. 

Karl is pointing to the extra cradle for the extra tube.

A view of the extra cradle from the back.

Yellow arrow points to the one-piece post extension.

Karl is pointing to the extra adjustment for the C# trill key height.  We couldn't capture the actual adjustment in this photo, but it is a very small piece of felt under the key.

Flute Scales

By Steven Wasser

  

The flute scale determines how well the notes play in tune to each other, octave to octave, and also determines the timbral balance of the notes.  From a mechanical standpoint the flute scale is a function of the following:

• the diameter of the flute tube or “bore”
• the size of each tone hole
• the linear location of each tone hole along the flute tube
• the height of each tone hole

Theobald Boehm developed the basis for today’s flute scales.  Verne Powell initiated an improved scale when he started producing his own flutes with the Powell Scale in 1927.  The next major improvement in scale design was accomplished by Albert Cooper in 1974.  Powell was the first major flute maker to introduce the Cooper Scale, and did so in 1975.  There are several other “modern” scales in use today, including the Bennett Scale used by one Japanese flute maker, and the Deveau Scale used by Haynes. 

Today Powell uses a modified and (we believe!) improved version of the original Cooper Scale which we call the Modern Powell Scale (or just Powell Scale, for short).  When testing instruments for scale we strongly recommend that you consider not only intonation, but timbral balance as well.  A new flute should sound like one instrument, not three separate instruments.

Scale should not be confused with the pitch of an instrument.  Pitch relates to which “A” the instrument has been designed to produce (e.g., A-440, A-442, etc.)  Powell instruments made for the U.S. market are typically pitched at A-442, and play well in tune from A-440 to A-444.

Tone Hole Leveling

Our finishers spend quite a bit of time padding flutes -- making sure that the pads are flat, shimmed, and level in the keys.  However, if the tone hole crown (top of the tone hole) is not level, all of that hard work would go to waste!  So, one of the most important steps in the finishing process is leveling the tone holes.  This process is done with both drawn and soldered tone holes. 

As with many steps in the finishing process, each finisher will have his/her variation on technique, but Karl Kornfeld demonstrated the process to us recently.  He first takes a magic marker to mark completely around the top of the tone hole.  Karl uses a green marker, although he said that any color would work.  He prefers not to use blue since the protective tape used on the flute is blue.  He then takes a small piece of a flat file and wraps it with a piece of 1200 grit sandpaper.  The flat file provides a flat surface for the sandpaper to work with in the process.  He then takes the wrapped flat file and gently sands the tone hole crown until the green marker ring disappears.  Karl shared, "If it's done correctly, it looks like a silver ring that is glowing green."  Glowing?  Well, in other words, because the tip of the magic marker is wider than the tone hole crown, a bit of marker will remain inside the tone hole -- which gives the "glow" after the green marker on the crown is sanded down.  After sanding the crown, if it looks like the silver ring is not complete (spots of green still visible on the crown), that means that there may be a low spot.  In this case, the crown must be leveled a bit more to make it flat.  Karl said that the lowest spot on the tone hole crown determines how much leveling needs to be done. 

Obviously, all this hand work takes extreme care and expertise.  The exact amount of pressure to use and actual technique comes from much practice.  As Karl mentioned, this process is extremely critical for seating pads properly -- and for making sure the entire flute mechanism fits and functions as it should as well!

Marking the tone hole crown.

Crowns marked all the way around.

Flat file

Flat file wrapped in 1200 grit sandpaper.

Leveling the tone hole crown by sanding.

Green ring gone (silver ring "glowing green" now).

Green marker left on this ring shows a low spots.