In peaceful single player, there is no background music at all. Music discs in jukeboxes also produce no audio, even though music notes are visible. There are also no sounds indicating nearby caves and such. 

All other sounds are still there, like animal noises, villager/trader noises, footsteps, rain and thunder, just no music/cues. 

My game settings for music and sound effects are both set to 100%. My phone ringer, notification, and media sound settings are also at 100%.