I think the power of music is like anything else – it can be used for holiness, or the opposite. To me, the test is simple enough: what does the music inspire in the listener? If it is evocative of beauty, and grace, and elevated attributes, then it is a Good Thing, no matter the source of the words or notes (listen to Amazing Grace, for an example). Music should touch us emotionally.
On the other hand, if music inspires merely physical urges without an elevated spiritual component, then it is merely a gateway to behaving more like animals and less like Hashem’s people.
Today’s wedding bands cross the line a lot, probably because the “lower class” music works on a broad range of listeners who often don’t know much about music. But having been told by my wife of a great many weddings in which the women revert to highly suggestive, overtly sexual, dance, it seems sensible to dial it back. Simcha should not come at any price at all, and when wedding music brings things out in public that should only be private, it has gone too far.