Music Magazine Cover Research

Some examples of music magazines:

As you can see from these examples Music Magazines tend to use the colours Red, Black and White as these colours stand out from one another and draw in the customers' attention.

They also (especially in NME) often use a bold skyline with band names or articles in it and colours that stand out.

All music magazines involve a picture of their main feature (a band or artist) with headlines of the stories going to be included edited on top of the photo. 
Out of these magazine's "The xx" would most likely be in  NME  or  SPIN which are both alternative, prestigious magazines.