The following story is recounted in the book Alaap: A Discovery of Indian Classical Music, published by the Sri Aurobindo Society in 1999:
The name of Tansen is synonymous with Indian music. He was the state musician in the court of the mighty Moghul emperor, Akbar. One day, after listening to Tansen, Akbar was so thrilled that he asked him, "Tansen, tell me who was your teacher?" "Swami Haridas, my lord," replied Tansen. Akbar asked again, "Is he as great a musician as you are?" Tansen said very humbly, "Please, never compare me to my master. He is not a musician but music itself." Akbar was intrigued. "Then I would like to hear him sing." Tansen answered, "But he will never agree to come to court to sing." "Then we will go to him," said Akbar. Tansen was still diffident. "My teacher sings of his own will and he won't be happy if he is compelled to sing before the emperor." But Akbar was determined. "Then I will come with you, disguised as your servant."
So, Tansen and Akbar travelled far to where the sage lived in a hut, his temple of music. The sage received Tansen, his former pupil, and his servant Akbar, with love and affection. He listened to their request but remained silent. Three days passed. Then one day, just before sunrise, Swami Haridas began to sing. Akbar and Tansen were spellbound. It seemed as if the sound had no beginning and no end, as if the trees, the stones, and all living creatures had turned into music and forgotten themselves.
After some time, when the spell was broken Akbar and Tansen found that they were alone in the hut. Swami Haridas was nowhere to be seen. "Where is he?" asked Akbar. "He has left this place forever, fearing that we may come again and trouble him," replied Tansen sadly."
They returned to the palace, silent and indrawn. Several days passed, but Akbar could never forget the effect the song had had on him. One day he asked Tansen whether he knew the raga and the song that Swami Haridas had sung. "Yes, I learned it from him," replied Tansen. At Akbar's request, Tansen sat down and sang the raga as only he could. But Akbar's heart was not satisfied. "Tansen, you sang beautifully. But still, why is it not the same as when Swami Haridas sang?" Tansen answered softly and humbly, "My lord, I sing for you, the emperor among men. But my master sings only for the Lord and Creator of the universe. Herein lies the difference."