Hypothetical collaboration

Regina Spektor and Nick Cave. Just to hear their ridiculously different voices in strange cohesion with each other. All the high-pitched yelpiness with that dank, doomy Antipodean darkness would be such an interesting listen. Cave's previous collaboration with Kylie Minogue turned out great, and while Spektor's voice is definitively weirder than Kylie's, I imagine any potential collaboration would have the same effect.

knxlwedge's wonderful, light beats, loops and production coupled with Frank Ocean's smooth vocals would be awesome together. I'm thinking something along the lines of post-dubstep with an R&B influence (vocal samples and whatnot) for the intended style of music. That'd be so rad.

Rihanna and Sia. I think with Sia's writing and their voices together, they could create something magical. Plus, Rihanna needs to collaborate with some new people anyway. I think Kelly Clarkson and Macklemore could create something fun too. Kelly has got such a diverse talent in the music industry, I think she and him could work together well. They can both write beautiful lyrics together.

I'd also like to see Britney Spears and Lady Gaga collaborate on a song together, because why not?