Four-part harmony

[3] The effort required to perform four-part harmony varies greatly.

Pieces written in such a style can be usually executed by a single keyboard player, a group of 4 instruments (or singers), or even a large choir with multiple singers per part.

In the baroque era, a set of rules developed for voice leading in four-part harmony.

In such cadences, the leading tone (the seventh scale degree) must resolve step-wise to the tonic.

Nowadays, they are usually taught in music theory classes, but most compositions follow less strict rules, if not outright disregarding them.