This can be explained physiologically. All vowels primarily are made in the larynx by the vocal cords. The _coup de glotte_ really is the process of vowel-making without the aid of consonants. This process of vowel-making is so smooth and open that a succession of legato vowel-sounds can be produced with only one stroke of the glottis, the vowel sounds flowing into each other, or each, seemingly, issuing from the other. Consonants are formed within the upper cavity of resonance, the mouth, some by the tongue alone, some by the combined action of tongue and lips. Voice-color being largely determined by the resonance-cavities, the articulation of consonants in the resonance-cavity of the mouth covers the open process of vowel-formation and gives color to the resultant word and tone. Thus, when "love" is sung, although _l_ is not a strong consonant but one of a small group called subvocals, it is sufficient to cover and color the open _o_ production. The easy singing range of each individual voice usually is about identical with the pitch of its possessor's speaking voice. Training should begin with the highest tone of the easy singing range. The reason for this is that the higher tone requires a certain muscular tension which places the singer, so to speak, on the _qui vive_ to the importance of the task before him; whereas the greater relaxation on the lower notes might cause him to regard the problem as too easy. At the same time the higher note, still lying within the easy singing range, does not call for a strain but simply acts as a spur. Kofler gives six examples of easy singing ranges for as many voice-divisions, and adds to each the qualification "more or less," thus allowing for differences in individual voices. His easy singing ranges are as follows: [Music: Soprano: G4-E5 More or less Mezzo-Soprano: E4-D5 " " " Alto: D4-C5 " " " Tenor: E3-E4 " " " Baritone: C3-C4 " " " Bass: A2-A3 " " "] Reference having been made to vowels and consonants, it seems proper to add at this point something about diction in singing. The interpretation of a song is tone-production applied to the emotional significance of words. There seems little reason to doubt that the old Italian masters sacrificed many things, clarity of diction included, to beauty of tone. This they placed above everything. True, beauty of tone is the first essential of artistic singing, but it is not the only essential. If song is speech vitalized by music, then speech, the words to which music is set, has some claim to consideration. In fact, the singer's diction should convey the import of the spoken word with the added emotional eloquence of music.