How do you test a theme park? Presumably by inviting in some people for go on the rides who it wouldn't be too upsetting if they discovered missing safety rails or loose bolts.
Somehow, they've managed to find some people to do this testing for the ill-conceived Hard Rock Theme Park. They're calling it a Sound Check, because it's a phrase that has something to do with music but doesn't really make sense being applied to tests on rollercoasters, in much the same way that the theme of the park has something to do with music but not in any way that makes sense.
The park is happy with how it went, but not going into too much detail:
Competitive reasons? What, is there a giant swing-boat with Black Sabbath logos painted on the side down the street, ready to compete with the Led Zeppelin rollercoaster?