in regard to how songs are written i'll say something regarding Downtown - she does interesting things modifying the meter and rhyme ... apart from varying them in a more usual sense... the lead into the refrain has a cute little twist which "wakes you up"

the light's so much brighter there (briefly syncopated)
(migrates into new 'straight' rhythm)
you can forget all your troubles
forget all your cares
and go....

and the rhyming at the end of the refrain follows rhythm migrations too.

Petula Clark is also talented in her expression of her songs... she embodies the feel of the song.

there are some modern musicians who do clever things but... sadly there is also a lot of stuff out there that doesn't differentiate itself well, as being written by a perspicacious, sentient being.