Diamond Head is one of those bands that pop into your head when you hear the word "influential". However, I feel that for about 99% of that time, this is the only album that comes to mind...and I can see why. This is an album is not modern-sounding by any means, but dammit, it's awesome. This is actually pretty diverse. It features elements of blues rock, hard rock, and some garage rock, as well. For this reason, even people who don't like heavy metal could find themselves listening to this masterpiece, every once in a while.
The music on this album is pretty reminiscent of bands such as Led Zeppelin and Black Sabbath, but it also managed to keep up with the changing sound of its genre. It's just a bit more blues-influenced, especially with the vocals and guitar work. This is also shown by the prominence of a pretty smooth bass. Colin Kimberle is not the most talented bassist out there, but he has some pretty nice bass lines here. Not really too much to say about the drumming, other than it doesn't suck. It keeps the music together. There is one song that breaks away from the usual sound of this album that I have to mention. "Am I Evil?" is much less bluesy and mainly just straightforward heavy metal. It's definitely the heaviest song on the album and has a pretty down-tuned, crunchy riff. Sure, Angel Witch had down-tuned, heavy riffs on their self-titled debut album, released in 1980, as well, but this album was recorded a year earlier. So for 1979, you can't get much heavier than this. This is probably why this is the most well-known song on the album.
There are two things that stand out to me the most on this album. One is definitely the vocals. Sean Harris delivers some quite soulful, bluesy vocals on this album and he has an absolutely amazing ability to shift pitch. He sounds very Howlin' Wolf-influenced (minus the growling tone), as well as quite a bit of Robert Plant. He puts quite a bit of chest and throat into his voice, which results in a voice that is both hollow and rich if that makes any sense at all.
The other thing that really stands out to me on this album is the guitar work. Brian Tatler is an extremely talented musician. His guitar work isn't exactly ahead of its time (with the exception of "Am I Evil?"), but it's really fucking good (and I just swore, so you know that I mean it)! His riffs are very catchy and have a pretty nice, thin tone. His solos, on the other hand, are also catchy, but in addition to that, are played with technicality. There aren't really a lot of guitarists out there who know how to do that. Being a guitarist myself, he has definitely inspired my to try a few new things out.
As musically dated as this album is, it isn't an album that hasn't aged well, in its genre. There is no older heavy metal album older than this one that I enjoy more. It took what heavy metal already was, and brought in some wider influences. Sure, heavy metal didn't really end up being like this, but this album has been an influence on many bands, most notably Metallica. If you're looking for a diverse, hard-edged album, this is probably a great album for you!