I think its different strokes for different folks.
Some people have a good ear for melody, and find the individual notes easily - some (like me) dont.

Some people (like me) are complete tarts and just love getting the room singing - for that you need the persistence to learn a couple of (or even three) chords. And the resolve to sit through episodes of Inspector Morse, with your fingers holding down the G chord, the D7 and if you're really serious the C chord as well.

Also ( a guilty secret) even on your own - you can fantasise a roomful of singers, or fiddlers and concertina players if you learn tunes in your head.