Duet.
The combinations most conducive to the proper movement of parts are those of two voices related within an octave
| 8 | [ | Sopr., | M.-sopr., | C.-alto |
| Ten., | Bar., | Bass. |
Movement in tenths, sixths, thirds or octaves (the last very seldom) will always produce satisfactory ensemble, and if the parts progress polyphonically, it need not happen frequently that they are separated by more than a tenth, or that undesirable crossing of parts will result.
Examples:
Sadko 99-101—Sopr. and Tenor (cf. [Ex. 289], [290]).
Servilia 143—Sopr. and Tenor.
Ivan the Terrible, Act I 48-50—Sopr. and Tenor.
Kashtcheï the Immortal 62-64. Mezzo-sopr. and Baritone.
Voices related in fifths and fourths,