Krishna's flute was so mesmerizing that it could even penetrate through the coverings of the universe. Once Krishna was playing His flute to call all His calves. He was very young at that time, a seven year-old boy. By the sound of His flute even the stones melted in ecstasy.
Certainly the rock on which Krishna stood melted, and got imprinted with His lotus feet and the cowherd stick. This is Charan Pahari, which is on the opposite side of the road from Vrinda-kunda.