There's no such thing as a person who cannot sing, unless they have some physical or mental malady that literally presents them from opening their mouths and singing. Sure, we're not all Freddie Mercury, but we all have unique voices that are to be valued. For me, all those X Factor people who warble and vibrato and mid-atlantic meah are awful singers, as they have none of themselves and a whole lot of other people. Give me an untrained voice any day of year.

That said, Ewan M's techniques - as I understand them from Jim's explanations - for teaching people how to physically become a more at ease singer - more comfortable, more themselves - sound ok to me.