Chandogya Upanishad, one of the oldest Upanishad has been written during the Vedic Brahmana period. Chandogya Upanishad is associated with Sama Veda. It is ranked ninth in the Muktika canon of hundred and eight Upanishadas. Chandogya Upanishad is the part of Chandogya Brahaman that contains ten chapters. The second chapter of Chandogya Upanishad contains twenty-four khandas.

1st Khanda
The 1st Khanda deals with the meditation on the fivefold Saman. One who meditates on the Saman as good inherits all the good qualities.

2nd Khanda
The 2nd Khanda again deals with the meditation on the Fivefold Saman. One needs to meditate on the fivefold Saman as the five worlds. The earth, the Prastava fire, the Udgitha the sky, the Pratihara the sun, the Nidhana heaven have been referred here according to the ascending order. The heaven, the Prastava the sun, the Udgitha, the sky, the Pratihara fire, the Nidhana the earth have been referred here according to descending order.

3rd Khanda
It deals with meditation on the fivefold saman as rain. The syllable Him is the wind that blows from the east, the Prastava is the cloud that forms, the Udgitha is what rains, and the Pratihara is the lightning and the thunder. The Nidhana is the cessation.

4th Khanda
It deals with meditation on the fivefold saman as Water. The syllable Him is the clouds that gather, when it rains it is Prastava; the Udgitha is the rivers which flow to the east, and the Pratihara is the rivers which flow to the west. The ocean is Nidhana.

5th Khanda
It deals with meditation on the fivefold saman as Seasons. The syllable Him is the spring, the Prastava the summer, the Udgitha the rainy season, the Pratihara the autumn, the Nidhana the winter.

6th Khanda
It deals with meditation on the fivefold saman as Animals. The syllable Him is goats, the Prastava sheep, the Udgitha cows, the Pratihara horses, the Nidhana man.

7th Khanda
It is meditation on the fivefold saman as the senses. Here, the syllable Him is smell (nose), the Prastava speech (tongue), the Udgitha sight (eye), the Pratihara hearing (ear), the Nidhana the mind.

8th Khanda
It is meditation on the sevenfold saman as the Speech. When the syllable Hum exists in speech, that is the syllable Him; likewise Pra is the Prastava, A is the Adi, Ud is the Udgitha, Pra the Pratihara, Upa the Upadrava, Ni the Nidhana.

9th Khanda
It is meditation on the sevenfold saman as the Sun. The sun is known as the Saman as he remains the same. All beings depend upon him, the animals, birds, men, devas, all depend on him. When he has risen it is Prastava, when rays move forth it is Adi, when he is midday it is Udgitha, when he is after midday and before afternoon it is Pratihara, when he is after the afternoon and before sunset, it is Upadrava, and when he is just after the sunset, he is Nidhana.

10th Khanda
It deals with meditation on the sevenfold saman through the number of syllables. The word Himkara has three syllables, the word Prastava also has three syllables, and thus, they are regarded as equal. Similarly, the word Adi has two syllables and the word Pratihara has four syllables and the word Udgitha has three syllables and the word Upadrava has four syllables. If one word is taken from the former and joined with the later they become equal.

11th Khanda
It deals with meditation on the Gayatra Saman. The syllable Him is the mind, the Prastava speech, the Udgitha sight, the Pratihara hearing, the Nidhana breath.

12th Khanda
It deals with meditation on the Rathantara Sama. It is a process of generating fire by rubbing two wood pieces.

13th Khanda
It is Meditation on the Vamadevya Saman. Here a man impressing a woman is Prastava; he lying with her is Pratihara; he giving time to her is Nidhana; and the finishing of the sexual act is also the Nidhana.

14th Khanda
It deals with meditation on the Brihat Saman. The risen sun is Prastava; the midday sun is the Udgitha; the afternoon sun is Pratihara; the setting sun is the Nidhana.

15th Khanda
It deals with meditation on the Vairupa Saman. The clouds that form are the Prastava; the raining is the Udgitha; the flashing and thundering are the Pratihara; the ceasing of the rain is the Nidhana.

16th Khanda
It deals with meditation on the Vairaja Saman. The summer is Prastava, the rainy season is Udgitha, the autumn is Pratihara, and the winter is Nidhana.

17th Khanda
It deals with meditation on the Sakvari Saman. Here, the Prastava the sky, the Udgitha heaven, the Pratihara the quarters, the Nidhana the sea.

18th Khanda
It deals with meditation on the Revati Saman. The Prastava sheep, the Udgitha cows, the Pratihara horses, the Nidhana man.

19th Khanda
It deals with meditation on the Yajnayajniya Saman. Here, the Prastava the skin, the Udgitha the flesh, the Pratihara the bone, the Nidhana the marrow.

20th Khanda
It deals with meditation on the Rajana Saman. The Prastava is the air, the Udgitha the sun, the Pratihara the stars, the Nidhana the moon.

21st Khanda
It deals with meditation on the Saman as linked with everything. The Prastava is these three worlds; the Udgitha is fire, air and the sun; the Pratihara is the stars, the birds and the rays; the Nidhana is the serpents, the gandharvas and the Manes.

22nd Khanda
It deals with different types of notes to be used while chanting of the Saman. All the vowels used in the Saman should be pronounced with resonance and strength

23rd Kahnda
The 23rd khanda has been written in praise of the Om Mantra.

24th Khanda
The final khanda deals with the various planes that the sacrificer attains after his worship.