Completely unsure of the proper way to do this, so I'm posting it here-A German musical group named "E Nomine" has a song by the name of "Wolfen" which involves one male singer singing in an extremely low voice, complete with rumbling throat as his part is that of a wolf, while the female singer has a clear, high song for hers. Come to think of it, they have more than one song like that, I just cannot name any at the moment.
If somebody was to either add that or tell me how, it would be great. I'd rather not risk messing it up.
A lot of the metal examples given appear to be more along the lines of "bands which use harsh and clean vocals", which is a much broader range than what the trope appears to describe. Newer Nightwish, Leaves Eyes, and Lacuna Coil- great. 3 Inches of Blood- not really? Cam Pipes' vocals are high pitched, but they are not remotely pretty. His falsetto is just as fierce and piercing as his co-vocalist. Rammstein, Opeth, Strapping Young Lad, Blind Guardian- these are bands which simply have one vocalist who can produce a variety of tones and moods. Opeth is a possibility, because his clean voice is so gentle, but it's not the pretty, delicate kind of clean vocals this trope describes. With Disturbed, his "clean" singing voice is still pretty aggressive, and his growled vocals aren't that extreme. The idea here is a pretty, high-pitched voice trading off with a low, beastly growl.
I think there should also be a section for hip-hop and R&B, because there are plenty of examples there.