As to the question which is the wrong and which is the right use of sound, it all depends upon the particular case. In one case a certain sound may be rightly used, in another case the same sound may be wrongly used, but whether it was right or wrong will be seen by the harmonious and inharmonious effects it produces. When a pitch is a natural pitch of the voice; and a person sings a note in that pitch in any pitch which is quite natural to him - that will be a source of that person's own healing as well as that of others.