Any Buddhists who know Avalokiteshvara Bodhisattva (觀音菩薩) will likely know "Pu Men Pin" (普門品) which is a chapter of the Lotus Sutra. Part of this chapter is about the merits or benefits of reciting the Name of Avalokiteshvara Bodhisattva. The rest is about the transformations of the Bodhisattva in order to save all sentient beings.
This chapter of Sutra has also the song version. So, those who love Buddhist song can recite according to the song. I just found a song of Pu Men Pin which is very nice. You can always find many Buddhist song at Youtube. Now, let's listen to Guan Shi Yin Pu Sa Pu Men Pin.