The Rigveda, containing hymns to be recited by the hotar, or presiding priest;
The Yajurveda, containing formulas to be recited by the adhvaryu or officiating priest;
The Samaveda, containing formulas to be sung by the udgatar or priest that chants;
The Atharvaveda, a collection of spells and incantations, apotropaic charms and speculative hymns