https://www.dzombak.com/blog/2021/02/Replacing-iTunes--Music-app--and-iTunes-Match--and-iCloud-Music-Library.html

sync-music-to-iphone.sh

#!/usr/bin/env bash
set -u

WHITE='\033[0;37m'
RED='\033[0;31m'
YELLOW='\033[0;33m'
GREEN='\033[0;32m'
NC='\033[0m'

if [ -e "/Volumes/Chris Dzombak's iPhone 11 co.brushedtype.doppler-ios" ] ; then
  if [ -d "$HOME/Music/160Kbps" ]; then
    rsync -vrkLh --progress --size-only --delete --exclude ".doppler" --exclude ".DS_Store" "/Users/cdzombak/Music/160Kbps/" "/Volumes/Chris Dzombak's iPhone 11 co.brushedtype.doppler-ios/Documents"
  fi
else
  echo -e "${RED}[!] Doppler on iPhone does not appear to be mounted..${NC}"
  echo "    Perhaps iExplorer is not running, or the iPhone's name has changed?"
  exit 1
fi

umount "/Volumes/Chris Dzombak's iPhone 11 co.brushedtype.doppler-ios"

echo ""
echo -e "${GREEN}✔ Complete!${NC}"
sleep 2