Flute is the oldest musical instrument known to mankind. Everyone is attracted towards the melodious sound of flute, which is Lord Krishna's favorite instrument. Bamboo flute is the only musical instrument which is most natural and does not contain any mechanical parts. This is the reason the flute is very close to Nature and sounds very melodious when played in an atmosphere surrounded by Nature. Flute has been mentioned in the Puranas which were written thousands of years ago.
Flute along with Mouth Organ is one of very few instruments which are portable. You can carry a short flute in your pocket and can carry it anywhere with ease unlike most other instruments which are very bulky. Flute sounds best when played in the atmosphere surrounded by nature. For example, if you take a short flute to mountains or a thick forest and then play, the echo of the sound bouncing back either from the leaves of the trees or from the mountains is simply very delightful. Every flute player in such circumstances receives a celestial experience. Nature actually talks back to you. Flute being the most natural instrument goes very well with the nature. Even while playing flute you can see that birds start chirping and try to talk to you through their singing. Although it sounds very melodious, the flute player of course cannot comprehend as to what the birds are trying to communicate.
Once, Lord Krishna asked his devotees what they would like to become in his hands. Some said the lotus, some the conch, some the chakra and so on, but no one mentioned the flute. Krishna advised them to become his flute. In his discourse to his devotees, he said that in the human personality structure, as in the flute, there are 8 main spots: The five organs of perception, mind, intellect, and ego. If you get rid of your ego and become like a hollow reed flute, then the Lord will come to you, pick you up, put his lips and breathe through you and out of the hollowness of your heart, the captivating melody will emerge for all creations to enjoy. But if you will continue your attitude of dislike, hatred and jealousy, the Lord will distance himself from you, since you will be useless for his purpose.