In a conversation with George Harrison, John Lennon and Yoko Ono at John's estate in September, 1969, Srila Prabhupada explained the importance of music and sound to 2 of the world's most famous musicians.
"Music...the Vedic mantras were all thru music. Sound waves, sound waves are full of music....samagah means the followers of the sound waves...
"Gayanti...they are always in music. Thru musical vibration they are approaching the Supreme. Gayanti means singing. So Vedic mantras and sound.
"This whole Bhagavad Gita and Srimad Bhagavatam can be sung very nicely. And Vedic mantra chanting, simply by hearing the vibration people will be benefited. Even they do not understand."
Srila Prabhupada then launched into a 4 minute mellifluous a capella song of verses from the Bhagavatam, as George, John and Yoko sat and listened.
Prabhupada concluded his demonstration to the Beatles with these words: "Veda mantra.... Vedanta Sutra... simply by transcendental vibration of sound, everything can be achieved."
That same message Prabhupada gave to the Beatles, he delivered to all of us, repeatedly, in his lectures, conversations and books, and literally in his life as a teacher and guru. In fact, everything he did was predicated on his faith in transcendental sound vibration. This faith was not one of idealism or ideology, of religion or fanaticism. It was a faith of realism, based on a transparent, confidential relationship he had with his guru and with Krishna, and supported by his constant remembrance of the maha mantra.
He drew for us a perfect standard for measuring a transcendentalist, someone who lives within the waves of transcendental sounds.