Idle question - what is this singing style called?

[BlackAmericanoNoSugar]

It's what I think of as old-fashioned, where the voice sounds a bit distant and fuzzy as though there is slight interference. Can the singer just do that with their voice or is it a particular microphone type or is it done on the mixing desk?

Like the first verse of Pumped up Kicks or the first verse of Smooth

Harmonica microphone.

Thanks ElenaSt, so it's the microphone that does it. Do you know how it works (in a technical way)? Is it something mechanical in the structure of the mike or is it an electronic alteration?

I believe it distorts the vocals giving it that retro sound.

there's various vocal effects applied to get that sound, envelope filter, phase, reverb. it doesn't have just one name

I actually just think it's edited in post-production. In the same way you can edit a photo in a million ways with technology (brighter, more contrast, coloured filters etc) you can use technology to edit sound (change the pitch e.g. high or low, make it sound more grainy, more electronic, and there are indeed filters to create certain effects)

I've had a look at the Foster the People video again and I can see that the lead singer is holding a harmonica mike in his hand. I can't actually see the mike but the way that he's cupping it in his hand is the way that it was demonstrated in ElenaSt's links.

That should be 'mic' not 'mike', shouldn't it? I thought it looked wrong as I was typing but it sounded right.

yes so it's a combination of microphone, pre-desk effects and production (software) effects most likely. I don't think you'd get the exact sound just by using that mic