Do Re Mi Fa So La Ti Do (A relative scale)
Bansuri use a relative scale, similar to the 'do, re, mi' concept. The notes are not measured in pitch (hertz), but are in relation to the first note. Western scales are usually 'absolute', based on 'A = 440 hertz' and 'middle C' which is 261.626 hertz, so that each note is measurable and can easily be repeated anywhere around the world, on any properly tuned instrument. This is possible because 'hertz' are measurable units of vibrations per second. Relative scales can start anywhere, so 'do' might be 'C' or it might be any other note or a note that is unrelated to western pitch. Furthermore, the notation system is based on finger position, rather than tone. What this means is that;
Songs can be played on any bansuri, regardless of flute length. Key is not a constraint. The same tune will sound different on 2 flutes of different keys, but the playing and notation method will not change. The `notes` represent finger positions, not tones.
Bansuri have 6 playable holes (usually), and the basic scale starts with the top 3 holes closed. This note is 'Sa'. The basic scale is as follows; (I have added rainbow colours for ease of visualization).
Sa Re Ga ma Pa Da Ni Sa
Sa (Top 3 holes closed)
Re (Top 2 holes closed)
Ga (Top hole closed)
ma (Top hole half closed - I use a small 'm' here, because there is also 'Ma'.)
Pa (6 holes closed)
Da (Top 5 holes closed)
Ni (Top 4 holes closed)
From this point we will reach Sa one octave above our starting note, with the same finger position as we started with, 3 holes closed. The upper octave is reached by changing your mouth shape (embouchure) which refocuses the air. Bansuri can play two to two and a half octaves, more on this later!
The Notation System
We need one system for the lower octave, one for the middle octave and another for the upper octave.
For the lower octave, we write;
,S ,R ,G ,m ,P ,D ,N
However, bansuri cannot play the first 4 of these notes, and so you will not see them notated in bansuri music. The first complete scale on the bansuri starts in the 'mid octave' at S.
The full basic scale is;
S R G m P D N
Even though this scale is notated without lower or upper octave marks, on bansuri, the first 4 notes are made by blowing the lower octave, but to reach the next 3 notes you will have to alter your embouchure to find the next octave for those finger positions. This seems counter intuitive at first, but makes sense if you keep in mind that the scale begins with 3 holes closed.
'S 'R 'G 'm 'P 'D 'N are used for the octave above.
Half notes (called 'Komal Swara') are frequently played, and are notated using small letters (lower case alphabet), as in 'ma' in the basic scale.
,d (Five and half holes closed, lower octave)
,n (Four and a half holes closed, lower octave)
r (Two and a half holes closed, lower octave)
g (One and a half holes closed, lower octave)
m (Half a hole closed, lower octave) * Although this note is a half note, it is not considered 'Komal Swara, as it is included in the natural scale.
M (All holes are open, lower octave) * The natural scale is played with the note 'm' as a half closed note. But sometimes scales will call for this note to played totally open. This is notated as 'M'. So during the practice sessions, if you see 'm' you will know this is maplayed with the first hole half closed, and 'M' is played with the first hole totally open.
Songs can be notated without an indication of octave, or showing S rather than ,S for the sake of ease. Songs are handed directly from teacher to student by playing rather than as a score, so the notation system is not always 100% accurate.
Common student flutes are tuned to Sa = G or shorter, such as G＃. These flutes are short enough for most beginners to be able to play. Most concert flutes are Sa = E, but these are longer and require more skill to play. Longer flutes have deeper notes but lack the responsiveness and expression of higher flutes. For children (aged between 7 - 14), a Sa = C is a suitable sized flute.