Harmonium Research & Promote Institute 
Pandit Pundalik N. Bhoir writes .......
To some extent this instrument was preferred & considered by some veteran musician. As I have observed after the year 1970, some of these musicians successfully used this instrument in Indian Music. They were talented musicians but somehow they could not overcome technical difficulty faced by them, while performing on the instrument. May be because they were not technicians. They did not try to modify the instrument to get the desired effect from the instrument as far as Hindusthani Music is concerned.
For example :
When we press a single key on Harmonium we get a particular note. Suppose we press black II key (D sharp). As we press it gradually to the fullest we hear a full note. But in this process we have covered a distance of three ‘shrutis', viz
• We hear a fine note, as we press the key a little
• While we press further, we hear a better note
• And we hear a forcefully note when we press key fully
This way we experience the three stages, as we play a single note. In olden literature all these three notes are termed as ‘ Chuyt-Shadja' or ‘ Achuyt-Shadja'.
The distance between ‘ Kakli Nishad', ‘Kaishaki Nishad', Three Shruti Puncham' or ‘Chuyt Puncham' and ‘Achuyt Pancham' is only one one shruti as per olden books on Indian Classical Music. In reality these notes are hardly experienced. However, harmonium is the only musical instrument which gives us distinct experience of these notes.
Naturally the question that arises is to what extent one should press the key on keyboard ? In my experience, on finely tuned harmonium, pressing any key to 3/8 th of an inch gives a full fledged note. Similarly air driving bellow, ‘ Bhata' , is also of great importance. Its width, spring tension and volume of air stored in it are the things which matter a lot. Because it is the different amount of air pressure that gives different degrees of vibrations to the notes. Also there are different stages of air stocked in the bellow. Has anyone considered these facors ??
Lastly the most important is the tuning of the instrument. Harmonium is tuned to the western tempered scales as compared to Indian Classical Music. How can then Indian Classical Music be played with this kind of tuning. Has anyone thought in this direction??
I started thinking from this angle while working on Harmonium. In seventies I was running a Harmonium workshop in Mumbai. I was all the time mediating / experimenting as to how to eliminate the drawbacks in Harmonium so as to make it a perfect accompaniment for the Indian Classical Music.