Samagana
Sāma is composition of words in Rigvedic hymns from notes. The hymns of Rigveda form the base of Sāmagāna. Sāmagāna is not merely a name given to singing hymns of Veda but represents the philosophy and science of uniting thought, sound and music. Sāmagāna is purpose of creation of Samaveda. Sāma Veda Sāma is singing of hymns from Rigveda alone and not from other Veda-s. "richi adhyoodham sama" ऋचि अध्यूढ्रम साम (Chhandog Upnishad 1.6.1). Hence Sāma is composition of words in Rigvedic hymns into notes. The richā-s or hymns of Rigveda are called yoni or ādhāra as they form the base of Sāmagān. In musicological parlance Sāma Veda has taken mātu (words) from Rigveda and provided dhātu (notes) to these words. (Bharatiya Sangeet Ka Itihaas. Dr. Thakur Jaidev Singh. Calcutta: Sangeet Research Academy, 1994, pp. 35 – 72) Parts of Sāma Veda Ārchika.आर्चिक् Only a few hymns in Sāma Veda Samhita were not based upon richa-s taken from Rigveda. The bulk being based on Rigveda is known as Ārchika. It has two parts. Poorvārchika. पूर्वार्चिक 585 Richa-s are sub-grouped into 6 Prapāthaka-s. Each Prapāthaka has two Ardha-s. Each Ardha has 10 Dashati-s. A collection of ten (here, hymns) is called