Al Stewart always maintained that Ralph McTell stole the tune for "Streets of London" from his earlier song "Oh Samuel, How You've Changed". It is perfectly possible to segue both songs seamlessly with "City of New Orleans"!

For as long as songwriters stick to the standard 12-note scale. conventional chord progressions and modulations, some close duplications are almost inevitable.

Think of poor old Pachelbel, if he had lived to collect the royalties from every tune based on his "Canon in D", he'd be wealthier than McCartney!

"Plagiarise - but, please, call it research!" Tom Lehrer.

Alan