Before responding to this question, I would like to make some observations as a preamble. It is a well-known fact that every child requires / should have, an outlet to express his / her emotions. As a follow up of this dictum, it is the duty of parents to ensure that the child has such opportunities. With regard to specific question about teaching sitar, I assume that concerned parents would have ascertained that their child has an aptitude for and interest in music and within that in instrumental music and within that in sitar music.
It would be advisable to acquire a small sized sitar to fit into the height of the child so that he / she does not have to carry a heavier instrument and stress his / her (especially) left hand, upto the frets difficult for him / her to reach.
A child of 10, I assume may be with persuasion – would adjust to the required baithak, holding the sitar at 45 degree angle and placement of both the hands (picture in Trainer’s manual).
Depending upon the capability of the child simple sargam should be taught to start with. Each note should be played 4 times (da – ra – da – ra etc.), similarly all the notes going up the scale and coming down the scale. In response to the question, I would like to advise as follows:
a. It would be easily agreed that the level of taleem should be in keeping with capability of the student. This dictum would apply to all ages and not necessarily to children below 10.
b. It would be useful to ensure that the concerned student should have a reasonably good sitar which he /she can hold and sit comfortably with the instrument in position. This tenet would apply irrespective of age.
c. If the student is an adult, he might have had training earlier from a sitar player. On the other hand, children below 10 may not have any earlier training. It would be therefore easy to teach children because they would not have any preconceived notions compared to an adult who might already have taleem which would reflect the style and technique of his / her earlier teacher.
d. In conclusion, I would mention that whilst teaching a child care should be taken to ensure that the child enjoys what he is doing. I remember having witnessed Ustad Vilayat Khan teaching Shujaat when he was very young. He used to coax / cajole him to sustain his interest and enjoy the process of learning. For an adult assuming that he has reasonable musicality, one should follow the techniques described in detail in the Trainer’s manual.