Let's be honest, if you are reading this review then you are already considering buying this album or you are wondering what it's all about. Well, let me lay it out on the line right now.
If you enjoyed the debut album then you will love this, if you are a fan of other battle/niche Metal bands (like TURISAS), then you will properly enjoy this; if on the other hand you like a bit or seriousness in your music or something a little more straightforward then you wont enjoy this, because at its very core, ALESTORM's Black Sails At Midnight is a fun, pirate themed jaunt through Metal madness.
2008 saw the release of the debut album, Captain Morgan's Revenge, a fun and fresh take on an emerging trend (using themes as main focus to music) and the pirate Metal setting allowed ALESTORM to build up a strong reputation on the live circuit for their rowdy shows which sent all those who couldn't handle the rowdiness of drunken pirates to the brig, but all those that could, well they got to sail the high seas and plunder the musical treasures.
OK, I'll stop with terrible pirate themed comparisons (for now). The question on the fans (and haters) mind was whether ALESTORM would be able to take this from being an 'one off' novelty, or could they push the theme forward and mature their sound; well that is exactly what the Scottish four piece has managed to do.
Black Sails At Midnight is actually a surprisingly well-put together album; building on the core sound, this album has everyone going full steam ahead and really pushing themselves to their full potential. Everything sounds exactly like you want it to, the music is both epic in its scope and scale, at times horns, brass and other orchestral instruments sweep into the music building massive amounts of atmosphere. Giving this just one listen is enough to see how diverse this album is compared to the debut, songs move easily between the epic drawn out sections, into thrashy as hell riffs that you could quite easily bang your head to. The title track is a great example of this, an atmospheric pirate Thrash fest, would be the only way I could possibly describe it!
The singer of course deserves a special mention, his voice lends incredibly well to the pirate style, sounding incredibly rough and piratey for the duration. To be honest I was a little upset to find out these guys weren't actually real pirates!
The two core components to this type of music are: whether the music creates an authentic sound and atmosphere (check) and whether the lyrics are of the correct subject matter. You will be happy to know the lyrics are still completely ridicules and cheesy, then again what else would you expect? The subject matter ranges between looting, drinking, drunken sea shanties about looting and drinking, oh and of course, hunting mythical sea creaturesΙ and well that is about it. Then again if you are buying this I am sure all you want is an authentic pirate experience.  
ALESTORM have created songs that lend themselves to two things: perfect accompaniment to drinking (rum is optional) and then music to dance too when you are drunk. The album closer is a perfect example of this, a cover song that was originally done by the band PIRATES OF THE SEA (Eurovision 2008 failures), which they have taken from the sorry state that it was originally in and turned it into something that sounds like a pirate folk song that you would expect to hear old drunken sailors singing in a old tavern.
At the end of the day if you enjoy pirate/battle/insert weird niche genre metal then you are going to enjoy this album. In fact if your biggest passions in life include; watching pirates of the Caribbean and drinking rum, then you are going to love this album. If you on the other hand you aren't looking to for an album that is mostly a light-hearted romp through a pirate fantasy then of course you wont enjoy it. It offers exactly what it says on the tin and doesn't try to branch out at all.
But hey, if you listen to this album and a smile isn't brought to your face, then it ye best be prepared to be damned to Davey Jones's locker for all eternity ye filthy landluver!