Adi thalam (Sanskrit ādi tālà आदि ताल, literally “primary clap”/”primary rhythm” also spelled aadi taala, adi talam) is the name of one of the most popular thala or rhythms used in Carnatic Music. Its full technical name according to the Carnatic Music’s tala system is ” Chaturashra-jaati triputa thala”

Structure Of Aadi Thalam :

This tala has eight aksharas consisting of ‘1 Laghu & 2 Dhruthas ‘ which is 8beats per cycle, in case of Vilamba kaala or chouka kaley its 16beats per cycle ie. we need to put all the aksharam twice. Many kritis and around half of the varnams are set to this tala.
  In a carnatic classical concert, Usually a main performer chooses Aadi thalam to sing or play a main song of the concert & Mridangam artiste plays thani  avarthanam in that particular song & exhibits his talent & skills. Its also easy for audience to put thalam along with a song & all the nadais can be easily (without compromising) played by mridangam artistes & other percussionists too..

                                                                                                                                                                                                                                                                                 -Mysore vadiraj