Wikipedia gives us this description of the Guru Gita:
The Guru Gita (Song of the Guru) is a Hindu scripture that is said to have been authored by the sage, Vyasa. The verses of this scripture may also be chanted. The text is believed to be part of the larger Skanda Purana. There are several versions of the Guru Gita, varying from around 100 to over 400 verses.
In the Siddha Yoga tradition, the Guru Gita is considered to be an “indispensable text”. Swami Muktananda chose 182 verses to create a unique version of the Guru Gita, which has its own melody for chanting
The text of the Guru Gita describes a conversation between the Hindu God, Lord Shiva and his wife, the Hindu Goddess Parvati, in which she asks him to teach her about the Guru and liberation. Shiva answers her by describing the Guru principle, the proper ways of worshiping the Guru and the methods and benefits of repeating the Guru Gita. The text also gives the etymology of the word Guru, where the root gu stands for darkness, while the root ru stands for light. The term Guru is therefore explained as the remover of darkness, who reveals the light of the heart.
The chanting is done in Sanskrit (here’s the transliteration). The most important benefit from the chanting happens on a subtle level by the repetition and recitation of the particular sounds. Even listening to it is beneficial. But it is also good to know the translation as it will help build devotion, faith and connection with the Guru principle. Also, the kundalini shakti likes chanting. Listen to the chanting and follow along with the English translation of the Guru Gita in the video below. An English text version can also be found at yogalifesociety.