THE ROLLER CANARY 69 
Flute notes are sung in every pitch shown with the 
exception of the range given for Bass. 
Each single note represents the various degrees of the 
musical scale on which the tour named can be per- 
formed, but it will be well here to remark that birds are 
not limited to our musical notation, which consists of 
tones and semitones. Their song has no fixed gradations, 
but shades into quarter and even eighth-tones, and this, 
of course, enriches the modulation. 
The outside limit for the high tours is given as G 
sharp above the stave, but if the bird does not sing 
tenderly and softly, the performance may be faulty, even 
though it may only reach F sharp. 
The complete compass of the song is practically three 
octaves; the soft rustling tour of former days, known as 
Schwirre, stretched the compass higher. 
ON MEASURING THE BEATS 
It is possible to a certain degree to measure the beats 
in Bell, Hollow Bell, Schockel, Flutes and Gluck, as 
these tours are syllabic, but with Hollow Roll, Bell Roll, 
Bass, Koller, Schwirre, and Water Roll, it is scarcely 
possible, as these tours are more of a tremolo, trilling or 
warbling nature, so that scarcely any break up into 
syllables is noticeable. 
The style of syllable, the blending of various 
consonants, and the movement in the different keys 
constitute certain melodic entities which are called Tours. 
By analysis of their structure, t.e., their composition, and 
the manner in which they are built up, as also the ground 
tone (vowel key sound) on which they are sung, all these 
tours may be divided into three large groups :— 
