Burzum_Maiden
I am the table
Back in those days singles were as important if not more important than LPs, especially when it comes to influencing a sound. The NWOBHM movement was almost entirely based in singles.
I'm gonna segue for a minute and say it's always been that way for popular music. Blues was all about the single, as was rock and roll in the 50s, and jazz. And if you look into the abortion that is the modern pop music industry (I would strongly advise against doing such a thing, and I look up to you if you somehow survive the trip) no one buys albums anymore, they all buy singles. Artists in pop music today never bother with big PR campaigns for albums, because singles sell better in popular culture. They don't do well in the underground, because it's a marketing technique we would all cry foul over (for good reason), but it works for mainstream artists.