What are the main vocal parts in a choir?

The main vocal parts in a choir are indeed Soprano, Alto, Tenor, and Bass. This arrangement represents the four primary voice categories that are typically used in choral music.

Soprano voices are the highest and often carry the melody. They usually consist of women and children with the ability to sing high pitches. Altos provide the harmony and are generally lower than soprano voices, usually represented by female voices with a rich mid-range. Tenors, usually the highest male voices, often sing the melody in male choirs and have a distinct and powerful sound. Lastly, Bass voices are the lowest in the choir, lending depth and foundation to the harmonic structure.

The other choices contain vocal parts that are indeed important but do not represent the standard classification used in most choral settings. For example, Baritone, Mezzo-soprano, Countertenor, and Bass-baritone are classifications that might be seen in specific contexts or vocal ensembles but are not the primary parts in traditional choir settings. Similarly, while terms like vibrato and falsetto relate to vocal techniques and capabilities, they do not define distinct choir parts. Contralto is another classification but is less commonly used compared to the established parts of Soprano,