I rushed the stage at a Wham concert for crying out loud!

在威猛乐队演唱会上，我冲到台前，大声尖叫着。

I think the reason you didn't understand this sentence is because of "for crying out loud." This is a colloquial expression used when trying to emphasize what you are saying. For example, if a five year old committed a crime and then was put in jail, you would say, "He's only five years old, for crying out loud." The context of your sentence is probably someone trying to prove that he is a music fan. It has absolutely nothing to do with crying or screaming or shouting.

我贸然地在强烈的音乐会舞台上大声的呼喊！

我在重打高声地大叫的音乐会冲了阶段！

在WHAM的演唱会上我冲到了台前大声尖叫着.

我冲到威猛乐队演唱会的台上,就是为了大声呼喊!