Page 13.	Line 6. Refer to page 24. Diagram II., F# and G? are both key-notes, and equally important on keyed instruments.
Page 19.	5 lines from below, add "of" between the words "root" and "B." After the word "harmony" on the last line, add "one always retiring." At the 11th line from below, No. 6 requires explanation. Professor Harrett is not a musician. If F?, E#, B?, and C? are included, there are 7 double tones; without these, only 5, viz., the black notes.
Page 20.	After the explanation of the colour blue, add "containing all colours."
Page 27.	Line 1. After the words, "major key-notes," add "13 if F# and G? are both included.
	Line 2. After the word "fourteen," add "to the different chords."
Page 31.	After the note B, G#, not G?.
Page 35.	Line 3 from bottom, for C? read E?.
Page 42.	Line 11. "And " should be "As."
Diagram I.	No. 1 is omitted to the lower C.
Diagram II.	No. 7 is omitted to B, and the key-note is wanting to the harmony of G?.
Diagram III.	In the secondaries of D, A should not be sharp.
Continued.	Nos. 1 and 2 are omitted to the lower C and D?.
Diagram IV.	The 3rd note of the trinities of F should be G.
	Line 1. The root F? is omitted. It should be coloured green, and F# ought not to be coloured.
Diagram VI.	The 3rd note of the trinities of F# and F? should be G.
Diagram VII.	Add to the 4th line of the explanation opposite: "The 8th circle is the octave of the 1st, and beyond our present powers;" and below the remarks that follow, add, "Notice that F# is not a root to any major key-note, and how in the growth of keys and the meetings by fifths the use of the double pole is seen, G? becoming D?."
Diagram XIV.	Add at the 3rd line, "the 8th circle is the octave of the first."
Continued.
Diagram XII.	For B#, second line, read B.