It's all true
It was first featured as a television advertising jingle for Brutus Jeans. The popularity of the commercial eventually led to the recording of "Jeans On" as a full-length song. 
They adjusted the lyrics to replace "Brutus jeans" with "old blue jeans" and titled the song "Jeans On".
It got to number 3 in the UK charts and a No. 1 in Germany.

# The advert #
https://www.youtube.com/watch?v=tmJ3Lo4FBQw

# Keith Urban - Jeans On Live #
https://www.youtube.com/watch?v=aUMJe17A2Io



0b1CoinObi

BTC_Bellzer

Music

Covers: Who Did It Better? - Track 12

Original
# David Dundas - Jeans On #
https://www.youtube.com/watch?v=jaV7ZLQkJv0

Cover
# Keith Urban - Jeans On
https://www.youtube.com/watch?v=ugCN9fhWnYc

The original from '77 was only a advertising jingle for Brutus jeans in the UK and it became so popular that it was then made in to a full length track.

For me it's Keith all the way