The texts those dealt with prosody or Vedic meters are known as Chandas texts. Here it describes about the rules for chanting the Vedic Mantras. Since the Mantras are set in metres, they require the knowledge for correct utterance and pronunciation. The Ṛgveda-prātiśākhya and the Nidānasūtra are two texts dealing with this śāstra. The chandaḥ sūtra of Pingala is a very well-known work on meter dealing with Vedic meter and also post Vedic Chandasas.