So the noisiest pub rock band on the planet have gone and done it again. Just 18 months after topping the charts with Black Ice, the phenomenal AC/DC are back at the summit of the UK album lists with their Greatest Hits record – a.k.a. the Iron Man 2 soundtrack.

For any band to gain back-to-back chart toppers in this day and age is an incredible achievement. To do it when you play rock is an even bigger coup. And to do it without selling your wares via iTunes is even more impressive.

In fact it’s fair to say AC/DC really are the biggest band on the planet right now.

If the Iron Man tie-up has propelled Angus and co. back into the public eye then of course they’ve been reconfirming their quality within the world of rock for two years now.

The brilliant Black Ice set the wheels in motion before the band’s Rock N Roll Train rolled into just about every major city in the world as the live event of 2009. Missed that? You missed out.

And even before the gobe went Iron Man mad AC/DC had been confirmed as Friday headliners for this summer’s Download Festival and without them many critics believe the iconic UK rock gathering would be a pale shadow of its riotous past.

With BJ and the boys Download (plus Slash and Aerosmith) is the must-see rock and metal shindig of 2010 and it’s no wonder organisers are plugging the chart-topping Antipodeans at every opportunity.

Of course there are some who might suggest AC/DC are selling out by putting their name to the Iron Man franchise. But let’s face it – there has never been a definitive Best Of released by the band and that’s exactly what the new soundtrack is.

Wandering into HMV and seeing banks of the famous AC/DC logo staring you in the face before you get a blast of one of the band’s biggest hits must have lifted the hearts of many a rock fan normally forced to trek to the bowels of the high street entertainment store before chancing upon the rock and metal section.

Linking up with such a huge Hollywood smash is a commercial masterstroke but there are hundreds of thousands of rock fans out there who will but the Iron Man soundtrack without ever watching the film. It’s the music – not the film – that has put AC/DC back on the top of the album charts.

It’s music that stands the test of time. Music that scares the shot out of your average HMV DVD buyer and music which laughs in the face of the other stuff clogging the Top 20 (the latest Free & Bad Company compilation excepted).

It’s no fluke that a band like AC/DC has bagged back-to-back number one albums – form may be temporary but class is permanent. And every track on the Iron Man soundtrack is pure class. (Rock And) Roll on Download…