Bhajan: It is to sing songs in praise of God and chant god's name accompanied by instruments like taal, mridangam, pakhavaj. There are 2 types of Bhajan: Chakri Bhajan and Songi Bhajan. Tukdoji Maharaj introduced a new form of Bhajan known as Khanjiri Bhajan.
In north India Bhajans composed by Saint Tulsidas, Surdas, Saint Meerabai, and Saint Kabir are very popular. In Gujarat Saint Narasi Mehta gave momentum to the Bhakti movement. In Maharashtra, the bhajan-keertan tradition was supported by Saint Namadeva.
Keertan: It is performed in a temple or in the precincts of a temple.It is performed by keertankar also known as Haridas or Kathekaribhuva. He has to dress in traditional way and very well informed. He needs to train himself in oratory, singing, musical instruments, dance and humour.
Traditionally, Naradmuni is supposed to be the founder of the Keertana tradition. Saint Namadev is known as the first keertankar of Maharashtra. Other saints helped the tradition to flourish.