That's kind of a moot point. An enormous amount of Alice In Chains' 'Dirt' is based off of Layne's drug problems but that doesn't stop the band from playing it live even after Layne no longer being around. SDV is a Dream Theater song - credited to Dream Theater (with songwriting credits to Moore of course). DT owns the song though, not Moore. They can and should play it more often because it's always been one of my faves.