Arjuna Dwells in Heaven and Learns from Chitrasena
Arjuna enters Amaravati and stands before Indra with joined hands. The king of the gods is delighted, offers him half his throne, and honours him. For the sake of weapons and learning, Arjuna begins to dwell in heaven — where Vishvavasu's son Chitrasena becomes his friend and teaches him everything the gandharvas know.
Arjuna entered that beautiful city, worshipped by gods and gandharvas. Hands joined in salutation, he stood before the king of the gods — the one with a thousand eyes.
Shakra, supreme among generous ones, was delighted. He offered Arjuna half of his throne. Then Vasava honoured him and touched his body.
For the sake of weapons and learning, Arjuna began to dwell in heaven, together with the gods and the gandharvas. Vishvavasu's son Chitrasena became his friend and taught him everything that the gandharvas knew.
Having obtained the weapons and having been honoured, Arjuna lived there happily in Shakra's abode, getting everything he wished for. He heard the sounds of songs and the splendid sounds of many musical instruments. He witnessed the dancing of the best of the apsaras (celestial dancers). He did not ignore those — he learnt them properly. But he specially devoted his attention to learning about weapons.
At that, the thousand-eyed lord was satisfied with Arjuna's wishes. And in this way, the period of his residence in heaven passed. Aranyaka Parva, Chapter 461