Bhakti yoga is the branch of yoga that connects you through sound with your own energy and through it with the Universal energy.
It is the Devotional yoga to divinity, understanding "Love is God and God is to Love".
Yoga is an altruistic concept and it is not unusual for a Bhakti Yogi to perform the tasks of others without expecting any favors in return, nor expecting any rewards for the tasks performed. According to the teachings of Bhakti Yoga, the reward is in the doing of the task itself and in the joy that this task brings to others around it and in giving the best of ourselves in it.
Through the meditative chanting of mantras or Kirtan it is possible and really easy to develop that devotional attitude of Love and to feel Love. It is not necessary at all to be a good singer nor to have a good voice, the only thing really necessary is to have the best predisposition and dedication, that is all, the rest simply happens if you really let go of the control and let it happen.