The Namboothiri Brahmans follow the Vedic traditions for their spiritual life and Smartha tradition for their social life. Their worship is an amalgamation known as "Sankaranarayanan", a combination of Shaivism and Vaishnavism. Namboothiris do poojas in temples based on Tantra Vidhi, a recent innovations. Tantra Vidhi clearly describes the moola (basic) mantras of the deities and their forms, paraphernalia, etc.
Vedic Tradition Of Namboothiries
Namboothiries belong to three different Vedic groups, those who follow Yajur Veda, those who follow Rg Veda, and those who follow the Sama Veda. There are, however, Namboothiries who are barred from chanting of the Vedas. These Veda-less Brahmins lost their right to chant Vedas due to some violations of the Dharma-sutra rules at some point of time.
The Yajur Vedic Namboothiries follow the Krishna Yajur Veda (prose and poetry combined Yajur Veda) and not the Sukla Yajur Veda (Yajur Veda with metre-poetry). The Yajur Veda is divided in to Samhita (literally 'collection of mantras'), Bramhana part (philosophy) and Aranyaka. The Namboothiries follow the Tythireeya Samhita. Namboothiries divides the Black (Krishna) Yajur Veda into Samhita and Sakha (Bramhana and Aranyaka parts). Samhita consists of about 48 modules known as Parchams. Sakha consists of 36 Parchams. Each Parcham has sub-modules known as Anuvakam (Sanskrit) or oath (Malayalam).
The majority of Namboothiries are Rig Vedic and are spread throughout Kerala. Then comes the Yajur Vedic ones, whose prime settlements are Perinchellur or Taliparamba of Kannur district and Perumanam (Cherpu) of Thrissur district. Less important ones are Irinjalakuda (Thrissur Dt) and Karikatt (Malappuram Dt). Samavedic Namboothiries form a minority and are located in pockets of Kottayam District and in Panjaal near Wadakkancherry division of Thrissur District.
Namboothiris, who are entitled to recite Vedams, have evolved a rich and diversified culture of Vedam recitation. Basically Namboothiries follow the Seeksha rules while chanting the Vedas. The Six Vedangas (literally Veda-body parts) are Seeksha (which describes the Sandhi and other rules in Sanskrit and also tells how to chant Vedas), Chandas (metre in poetry - ChandoManjari), Meemamsa (philosophy), Nirukta (etymology of Sanskrit language), Vyakarana (grammer) and Jyotisha (astrology). Most of Yajur Vedic Namboothiries (especially Boudhaayanas) follow the Seeksha of Vasishtha (Sage Vasishtha).
The Veda chanting method divides all words into Udatha (high pitch), Anudatha (low pitch) and Swarita. The Namboothiri Veda tradition is orally transmitted over the generations and is thought by many to be the oldest and most traditional and correct way of chanting the Vedas. Their recitation is quite different from traditional Vedam recitations in other parts of India. This is due to a variety of features, such as the pronunciation of Sanskrit in Kerala. An Important feature is nasalization, a feature of Malayalam in general which seems to be relatively ancient. (In Sanskrit it was called "anunaasika athiprasaram".) Another reason may be that a much larger percentage of Malayalam words are of Sanskrit origin than is the case with Tamil. It may also be connected with the isolated development of the Namboothiri tradition, which was not exposed to contact with other traditions. And lastly, though there have been many Namboothiri scholars of Sanskrit, there has not been a tendency to bring existing practice inline with the norms established in the past. Rather, the living tradition has been left to prevail and develop freely.
While all Vedic recitations are taught at home, there are two special schools for the teaching of Rigvedam, one at Thrissur and the other at Thirunaavaaya, in Malappuram district. The Thirunaavaaya School was formed by several Namboothiris and financed by Saamoothiri Raja (King Zamorin) of Malabar. The Thrissur school was supported by the Raja of Cochin. There are differences in the style of recitation of the two Rigvedi schools. The Thrissur school (Brahmaswam Madhom) has a few students even now, while the Thirunaavaaya school is not fully functioning. Fortunately, a few of its students are being taught at home. The Thrissur school recently started admitting children of families which originally followed Yajur Thirunaavaaya style. In the Yajurvedam there are also two traditions that differ slightly in style of recitation, the Peruvanam School tradition and the Irinjalakuda School tradition. Today, the Yajurvedam and Saamavedam are also being taught in private homes.