This article is from the Iron Maiden FAQ, by Vartan Narinian vsn@pobox.com and Steve Payne Sirpapa@aol.com with numerous contributions by others.
"Sanctuary" first appeared on the Metal For Muthas with "Wrathchild."
This is why neither one made it on the first album. I guess by the time the
single was issued Tony Parsons was no longer a member of the band so they
redid it with Dennis. "Wrathchild" was Adrian Smith's audition piece, and I
guess he must have done such a great job with it that they decided to stick
that onto the next single.
Already "Running Free" was a single, but only in Europe and I think this
single was performed by the quartet lineup Di'anno / Murray / Harris / Sampson,
which would make sense that "Sanctuary" would be the first thing done by the
lineup that would appear on the album, but since by now there were two versions
of "Sanctuary floating about in UK but never heard in USA, they stick on the
new version of "Sanctuary" which has the same lineup as the rest of the album
(in my opinion though it's the inferior version. Stratton's solos tended to
sound more or less the same from song to song).
"Twilight Zone" comes out as a single soon after Adrian joins, but again only
in the UK but not in USA. This is why it appears on USA pressings of Killers
but not in the UK and everywhere else, I guess.
Again, it makes sense to stick it on this album because the lineup that did
"Twilight Zone" is the same that did the second LP.
 
Continue to: