Canon EOS Rebel T6 Instruction Manual page 175

Background Music
You can play background music when you play back albums, normal
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movies, and slide shows on the camera (p.174, 219). To play
background music, you must first copy the background music to the card
using EOS Utility (EOS software). For information on how to copy the
background music, refer to the EOS Utility Instruction Manual.
Music recorded on the memory card must be used only for private
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enjoyment. Do not violate the rights of the copyright holder.
3 Shooting Video Snapshots
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