use strict;
use warnings;
my @types = qw( Artist Album Song Song);
while (<DATA>) {
    s!^/Volumes/WD/Not Migrating/Music/!!;
    my $type = $types[ tr/\//\// ];
    printf "%-6s : %-80s\n", $type, $_;
}
__DATA__
/Volumes/WD/Not Migrating/Music/Ana Tijoux
/Volumes/WD/Not Migrating/Music/Eminem/Ana
/Volumes/WD/Not Migrating/Music/Eminem/Ana Tijoux/Luchin/Luchin.m4a

Output:
Artist : Ana Tijoux

Album  : Eminem/Ana

Song   : Eminem/Ana Tijoux/Luchin/Luchin.m4a