Mysterious Music Heard by Apollo 10 Astronauts on Far Side of Moon

Apollo 10 astronauts heard and recorded strange "whistling sounds" resembling "outer-space music" while orbiting the far side of the Moon in 1969. The sounds were not released to the public for nearly 50 years. NASA later confirmed that the sounds were caused by interference between the lunar module and command module's VHF radios. The incident was mentioned in Michael Collins' book, who flew the command module alone while Neil Armstrong and Buzz Aldrin headed to the Moon's surface.