Hi all,
While the bridges are drying out from their soaking I thought I’d take advantage of the time to take care of a few bits and pieces that need to be done. The first of these tasks involve making the instrument transposable. Ernie, what does that mean? Ok, I’ll tell you.
As you may know, all instruments are tuned to a pitch standard. Certain instruments, like the trumpet, clarinet, flute, kazoo, nose whistle, etc. have their basic pitch set at the factory when they are built. Others, like the piano, harpsichord, violin, etc. can change their built-in pitches by re-tuning, de-tuning, un-tuning, or ignoring tuning. Unfortunately, these instruments often have to play together – as in an orchestra. To do this, all instruments must be tuned to the same pitch standard. Today, in most of the world, that standard is A-440 which means that the note A above middle C must vibrate 440 times per second. The noise you hear at the beginning of every concert (yes, even rock concerts) are the musicians tuning their instruments to that standard. The instruments that can’t be tuned, like the trumpet and its brothers and sisters are already factory tuned to that pitch and can only be adjusted slightly to accommodate slight variations in the standard.
Unfortunately for us, the current standard (A-440) is a relatively recent one. Back when harpsichords were originally built the standard pitch was lower than it is now. 300 years ago, most of the world used A-415 (or something close to that) as the standard. Many instruments today are built to that standard for people who like to play this old music at the original pitch. Until recently, if the harpsichord was to be played with these old-pitched instruments, it had to be completely retuned to the lower pitch. This involved re-tuning up to 183 strings, usually 2 or 3 times, due to instability. The next day, the same harpsichord might have to play with modern-pitched instruments and the whole process would have to be repeated, this time bringing the pitch back up to today’s standard. A royal pain, to be sure. There has to be an easier way – and there is. Take a close look at the ends of the keyboard in this picture.
Notice that there is space between the ends of the keyboard and the sides of the case. The back ends of each key must be in line with the 2 strings that key will eventually pluck. It’s confession time – I misled you in the last post. We didn’t drill 102 tuning pin holes (2 for each key), we actually drilled 104. There will be two extra strings at the bottom end of the instrument that have no key with which to play them. Unless ...... we slide the whole keyboard ½” to the left. As the space between strings is ½” the bottom key will now be in a position to play these two extra strings making the top two strings orphans with no key to play them with. This is how we avoid re-tuning all those strings every time the pitch standard changes. When the keyboard is slid ½” to the left, the A key will now pluck the G sharp strings (which just happen to vibrate a 415 cycles per second). The player will think he’s playing the note A but the sound produced will actually be G sharp. This, the pitch level of the harpsichord has been transposed down to the old pitch standard. To return to the modern pitch standard, all we need do is slide the keyboard to the right ½” and the keys will now play their original strings. Pretty neat, huh? Does this mean the player has to carry a ruler with him to measure the ½” distance he needs to slide the keyboard. No – there’s a better way. Here’s how we do it.
Traditionally, a wooden block is inserted at each end of the keyboard to fill the space between the end of the keyboard and the case side. What we’ll do is make 3 wooden blocks instead of two. One of these 3 blocks (called Cheek Blocks for reasons only Ima and Yura know) will be exactly ½” wide. As there is 2 ½” combined space between the two ends of the keyboard and the case sides, the remaining two blocks will each be about 1” wide. These two 1” wide blocks will be screwed to the sides of the keyframe and move with the keyboard when it’s slid. The ½” wide block is attached to nothing – it is removable. To play at the old-pitch, the player removes the ½” block, slides the keyboard as far as it will go to the left, and inserts the ½” block into the ½” space left at the right end of the keyboard. To return to modern-pitch, the player removes the ½” block from the right end of the keyboard, slides the keyboard as far as it will go to the right, and inserts the ½” block into the ½” space now at the left end of the keyboard. That’s all there is to it. Let’s build the blocks.
The cheek blocks will be 2” high so we’ll start by gluing up 3 pieces of ¾” poplar.
When the glue has set, we slice the blank apart into two 1” wide pieces and one ½” piece.
At this stage, the blocks will work fine but look rather plain. Let’s fancy them up a bit. First we’ll glue a ¼” cap to the front of each block to hide the edges of the 3 plys they’re made out of.
Next we’ll cut a ¾” high x ½” deep rabbet to allow the front edge of each block to fit over the case front molding. Behind the rabbet and 45 degree angle is cut to make it easier to remove the keyboard and cheek block from the case.
Now we’ll use some of the same molding we used on the top edges of the case and some poplar stock the same thickness as the molding to decorate the tops of each cheek block.
Here’s a photo of the 3 cheek blocks after the moldings have been glued on and trimmed.
The outboard rear edges of the two wide cheek blocks are rounded to avoid accidentally damaging the case when the keyboard is removed or replaced.
Next, the two wide cheek blocks are screwed into place at each end of the keyboard.
Here’s the keyboard installed in the case in the modern-pitch position (keyboard slid to the right). Note the ½” removable cheek block on the left end.
Here’s the keyboard installed in the case in the old-pitch position (keyboard slid to the left). Note the ½” removable cheek block on the right end.
One thing left to do. In the next photo, notice the space between the top surfaces of the keys and the nameboard. This space will be filled by a thin strip of wood called the Nameboard Battan. This is where the builder’s name goes.
The Nameboard Battan is 1 ½” tall and about ¼” thick. A decorative edge has been routed into its top front edge.
And finally, everything is installed into the case. The Nameboard Battan will be screwed to the bottom of the Nameboard after the keys get their keytops installed to make sure there is enough clearance between the keytops and the bottom of the battan.
And that’s all you ever wanted to know about a Harpsichord Keyboard Transposer – probably more.
The bridges are still drying from their soaking so next time we’ll cut up some ebony and bone and install keytops onto the keys.
One final note – putting links to previous parts of this Project has become a problem in several ways. Bas has come up with a great solution. For the next 300 posts in this series (I’m just kidding – I hope) I’ll include a link to a file that contains the url’s for all parts of this series for those of you who want to refer to them.
Till next time,
Ernie
While the bridges are drying out from their soaking I thought I’d take advantage of the time to take care of a few bits and pieces that need to be done. The first of these tasks involve making the instrument transposable. Ernie, what does that mean? Ok, I’ll tell you.
As you may know, all instruments are tuned to a pitch standard. Certain instruments, like the trumpet, clarinet, flute, kazoo, nose whistle, etc. have their basic pitch set at the factory when they are built. Others, like the piano, harpsichord, violin, etc. can change their built-in pitches by re-tuning, de-tuning, un-tuning, or ignoring tuning. Unfortunately, these instruments often have to play together – as in an orchestra. To do this, all instruments must be tuned to the same pitch standard. Today, in most of the world, that standard is A-440 which means that the note A above middle C must vibrate 440 times per second. The noise you hear at the beginning of every concert (yes, even rock concerts) are the musicians tuning their instruments to that standard. The instruments that can’t be tuned, like the trumpet and its brothers and sisters are already factory tuned to that pitch and can only be adjusted slightly to accommodate slight variations in the standard.
Unfortunately for us, the current standard (A-440) is a relatively recent one. Back when harpsichords were originally built the standard pitch was lower than it is now. 300 years ago, most of the world used A-415 (or something close to that) as the standard. Many instruments today are built to that standard for people who like to play this old music at the original pitch. Until recently, if the harpsichord was to be played with these old-pitched instruments, it had to be completely retuned to the lower pitch. This involved re-tuning up to 183 strings, usually 2 or 3 times, due to instability. The next day, the same harpsichord might have to play with modern-pitched instruments and the whole process would have to be repeated, this time bringing the pitch back up to today’s standard. A royal pain, to be sure. There has to be an easier way – and there is. Take a close look at the ends of the keyboard in this picture.
Notice that there is space between the ends of the keyboard and the sides of the case. The back ends of each key must be in line with the 2 strings that key will eventually pluck. It’s confession time – I misled you in the last post. We didn’t drill 102 tuning pin holes (2 for each key), we actually drilled 104. There will be two extra strings at the bottom end of the instrument that have no key with which to play them. Unless ...... we slide the whole keyboard ½” to the left. As the space between strings is ½” the bottom key will now be in a position to play these two extra strings making the top two strings orphans with no key to play them with. This is how we avoid re-tuning all those strings every time the pitch standard changes. When the keyboard is slid ½” to the left, the A key will now pluck the G sharp strings (which just happen to vibrate a 415 cycles per second). The player will think he’s playing the note A but the sound produced will actually be G sharp. This, the pitch level of the harpsichord has been transposed down to the old pitch standard. To return to the modern pitch standard, all we need do is slide the keyboard to the right ½” and the keys will now play their original strings. Pretty neat, huh? Does this mean the player has to carry a ruler with him to measure the ½” distance he needs to slide the keyboard. No – there’s a better way. Here’s how we do it.
Traditionally, a wooden block is inserted at each end of the keyboard to fill the space between the end of the keyboard and the case side. What we’ll do is make 3 wooden blocks instead of two. One of these 3 blocks (called Cheek Blocks for reasons only Ima and Yura know) will be exactly ½” wide. As there is 2 ½” combined space between the two ends of the keyboard and the case sides, the remaining two blocks will each be about 1” wide. These two 1” wide blocks will be screwed to the sides of the keyframe and move with the keyboard when it’s slid. The ½” wide block is attached to nothing – it is removable. To play at the old-pitch, the player removes the ½” block, slides the keyboard as far as it will go to the left, and inserts the ½” block into the ½” space left at the right end of the keyboard. To return to modern-pitch, the player removes the ½” block from the right end of the keyboard, slides the keyboard as far as it will go to the right, and inserts the ½” block into the ½” space now at the left end of the keyboard. That’s all there is to it. Let’s build the blocks.
The cheek blocks will be 2” high so we’ll start by gluing up 3 pieces of ¾” poplar.
When the glue has set, we slice the blank apart into two 1” wide pieces and one ½” piece.
At this stage, the blocks will work fine but look rather plain. Let’s fancy them up a bit. First we’ll glue a ¼” cap to the front of each block to hide the edges of the 3 plys they’re made out of.
Next we’ll cut a ¾” high x ½” deep rabbet to allow the front edge of each block to fit over the case front molding. Behind the rabbet and 45 degree angle is cut to make it easier to remove the keyboard and cheek block from the case.
Now we’ll use some of the same molding we used on the top edges of the case and some poplar stock the same thickness as the molding to decorate the tops of each cheek block.
Here’s a photo of the 3 cheek blocks after the moldings have been glued on and trimmed.
The outboard rear edges of the two wide cheek blocks are rounded to avoid accidentally damaging the case when the keyboard is removed or replaced.
Next, the two wide cheek blocks are screwed into place at each end of the keyboard.
Here’s the keyboard installed in the case in the modern-pitch position (keyboard slid to the right). Note the ½” removable cheek block on the left end.
Here’s the keyboard installed in the case in the old-pitch position (keyboard slid to the left). Note the ½” removable cheek block on the right end.
One thing left to do. In the next photo, notice the space between the top surfaces of the keys and the nameboard. This space will be filled by a thin strip of wood called the Nameboard Battan. This is where the builder’s name goes.
The Nameboard Battan is 1 ½” tall and about ¼” thick. A decorative edge has been routed into its top front edge.
And finally, everything is installed into the case. The Nameboard Battan will be screwed to the bottom of the Nameboard after the keys get their keytops installed to make sure there is enough clearance between the keytops and the bottom of the battan.
And that’s all you ever wanted to know about a Harpsichord Keyboard Transposer – probably more.
The bridges are still drying from their soaking so next time we’ll cut up some ebony and bone and install keytops onto the keys.
One final note – putting links to previous parts of this Project has become a problem in several ways. Bas has come up with a great solution. For the next 300 posts in this series (I’m just kidding – I hope) I’ll include a link to a file that contains the url’s for all parts of this series for those of you who want to refer to them.
Till next time,
Ernie