Flexibility.
Voices possess the greatest amount of flexibility in their normal octave. Women's voices are more supple than men's, but in all types, the higher voice is the more agile, sopranos in women, the tenor voice in men. Although capable of performing florid and complicated figures, different varieties of phrasing and the rapid change from staccato to legato, the human voice is infinitely less flexible than a musical instrument. In passages of any rapidity, diatonic scales and arpeggios in thirds come easiest to the voice. Intervals bigger than fourths in quick succession and chromatic scales are extremely difficult. Skips of an octave or more starting from a short note should always be avoided. Preparation should precede any extremely high note either by leading up to it gradually, or by the clear leap of a fourth, fifth or octave; but sometimes the voice may attack a high note without any due preparation.
Examples:
Snegourotchka 46-48 (cf. extract, [Ex. 279])—Snegourotchka's Aria (Soprano).
" 96-97—Lell's first song (Contralto).
Sadko 196-193 (cf. extract, [Ex. 122])—Hindoo song (Tenor).
" 203-206—Venetian song (Baritone).
Pan Voyevoda 20-26—Maria's cradle song (Sopr).