PREREQUISITE: Install platform-tools and https://github.com/google/adb-sync

sync_itunes_albums_to_android.sh

#!/bin/bash
set -eu

: ${ITUNES_MEDIA_DIR:="${HOME}/Music/iTunes/iTunes Media"}
: ${DST_MUSIC_DIR:=/storage/0000-0000/Music}

usage() {
  cat <<EOT
Usage: $0 [-x]

Options:
  -x        NOT dryrun

Environments:
  ITUNES_MEDIA_DIR="${ITUNES_MEDIA_DIR}"
  DST_MUSIC_DIR="${DST_MUSIC_DIR}"
EOT
}

abort() { >&2 echo "ERROR: $*"; exit 1; }
run() { echo "RUN: $*"; "$@"; }

opt_nargs=0
opt_dryrun=true
while (($# > 0)); do
  case "$1" in
    -h | --help ) usage; exit 1;;
    -x ) opt_dryrun=false;;
    -* ) abort "unknown option: $1";;
    * )
      case $((++opt_nargs)) in
        * ) abort 'too many arguments';;
      esac
      ;;
  esac
  shift
done

sync_opts=(-n)
if $opt_dryrun; then
  sync_opts=("${sync_opts[@]}" --dry-run)
fi

run adb-sync "${sync_opts[@]}" "${ITUNES_MEDIA_DIR}/Music/" "${DST_MUSIC_DIR}/"