could you put a link or something of the article
 
        
             
        
        
        
This is probably a joke but I'll answer anyway 
By 'cheeks' they mean buttocks so by "making them clap" is referring to them being so big/thick that they clap or make noise when you walk or move around or something. 
I probably got played lol but whatever 
 
        
             
        
        
        
The instruments are guitar and drums at least that what I hear hope I helped.