Don't create the new file if it has no data. Also make the Track portion optional so that the files do not become hidden with a ..

refactor_music_library.sh

@@ -75,7 +75,7 @@ find "$OLD" -type f ! -name "*".mp3 | sort | while read file; do
 	if [[ $status != 0 ]]; then
 		echo "*** FAILED: Exited with status '$status'."
 		echo "**** To troubleshoot, try running this:"
-		echo "ffmpeg -i '$file' '$file'.converted.mp3"
+		echo "ffmpeg -i \"$file\" \"$file\".converted.mp3"
 	else
 		echo "*** Success!"
 	fi
@@ -127,7 +127,9 @@ function migrate_music {
 	[[ ${#track} == 1 ]] && track="0$track"
 	echo "*** Track=$track"
 
-	new_file="$track. $new_file"
+	if [[ -s "$track" ]]; then
+		new_file="$track. $new_file"
+	fi
 
 	# Add the Album and Year.
 	album=""
@@ -209,6 +211,26 @@ function migrate_music {
 
 	new_file="$grandparent/$new_file"
 
+	# Check that the file has proper data.
+	skip=false
+	if [[ -z "$grandparent" ]]; then
+		echo "ERROR: Could not find Artist information."
+		skip="true"
+	fi
+	if [[ -z "$parent" ]]; then
+		echo "ERROR: Could not find Album or Year information."
+		skip="true"
+	fi
+	if [[ -z "$track" && -z "$title" ]]; then
+		echo "ERROR: Could not find Track or Title information."
+		skip="true"
+	fi
+
+	if [[ "$skip" == "true" ]]; then
+		echo "*** Skipping file, critical data missing."
+		return 1
+	fi
+
 	# Create the new directories if they do not already exist.
 	mkdir -pv "$NEW/$grandparent/$parent"