Types of Keyboards


There are two types of keyboard actions in harmoniums, vertical pivot pin and horizontal pivot pin, or those are my names from them.

Vertical Pivot Pin Style 

Bhava with One Key Removed

This is the most common type of key action used in portable harmoniums. When you press down on a key, the back of the key moves up on the pivot pin and uncovers the two holes above where the reeds are mounted. Air passes through these holes causing the reeds to vibrate. The picture below shows a close up of the back of the keyboard with one key removed. The two reed holes are plainly visible. The vertical “pivot pin" below the reed holes fit into a hole in the key and allows the key to pivot up and down. 

Key Parts


Springs for each key (shown in the picture above) press down on the back of each key so when the key is released, the key returns to the normal position and the reed holes are covered preventing them from playing.

Horizontal Pivot Pin Style 

This type of key action is less common in newer portable harmoniums but was used on older harmoniums and scale changer types.

The picture below shows this type of harmonium. [Note that in this picture, the back of the keys are lifted above the actuator arms in the back, which is not their normal position.] 

In this style of harmonium, the key and the lifter each have a horizontal pin which is pressed into a slot so that the key and lifter pivot at this point.

When a key is pressed, the back end of the key lifts up on the front end of the lifter, lifting the back end and opening the holes above the reeds.  

The harmonium in the picture is a “scale-changer” harmonium. The keyboard can be lifted and moved left or right three “keys” by means of a lever on the front. This allows the musician to play the keyboard in the key of “C” but transpose the sound so it could be A, Bb, B or C#, D or Eb (D#).  

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Horizontal pivot pin harmonium

Action Adjustment Screws

Tightening the small screw on the end of the key arm lifts the blue end of the key and will decrease the gap between the key end and the lifter and will raise the playing portion (key cap) of the key. Loosening this screw will lower the key cap and increase the gap between the key end and the lifter. 

Start by adjusting the key screw so that all the key cap heights are even.  If this screw is tightened too much, it can cause the lifter to raise up to the point that the key will sound even when not pressed. 

Once all the keys are level, then check for any leaky keys. Open the stops and place a weight (a 9 volt battery on its side works nicely) on the highest key so it is pressed down then start pumping the bellows. You should only hear the notes from the depressed key.

If all is good, then move the weight to the next lowest key and make sure the highest key is not leaky.

Key Bounce

Press each key down while pumping the bellows and let the key release. Don’t “slap” the key, just press and gently release. The note should stop fairly quickly and the key shouldn’t bounce. If it bounces a lot, then the spring on that key needs to be adjusted. Some bounce is normal. This is not an easy task so you may want to leave it to me or another repair person.  

The picture below shows the locations of the pivot pin slots (the pins themselves are not visible) and also the keys and lifters.

Scale Changer Keys Annotated

Key action on horizontal pivot pin harmonium 

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