Octave and subtracting a semitone. In a short time the thinking of other tones will not be required.
It should be clearly understood that the even intervals occupy a space and a line; the uneven intervals either two spaces or two lines. It is readily grasped at sight that
cannot be a 4th or a 6th.
To reach a 7th, strike the octave, and come back one, then sing the 7th direct. The addition or subtraction of a semitone, by the use of a sharp or flat, can be practised, and the names of keys and numbers of sharps and flats can all be added. (See "The Choir-Boy's Manual," companion-book to this.)
When the choir can sing the seven intervals of the octave, starting from a given keynote, they will, if attentive, count up from any other keynote and sing equally well.
On the blackboard mark a keynote, then all the uneven intervals, 3d, 5th and 7th, then the even ones, 2d, 4th, 6th, 8th.
Pupils should now be able to name the interval from the keynote, by placing a series of notes on the board and pointing to them, thus:
