The last
number one song of the 1970's was 'Escape (The Pina Colada Song)'
by Rupert Holmes.
The first
number one song of the 1980's was 'Please Don't Go' by KC & the
Sunshine Band.
The song that
was heard at the end of every episode of 'WKRP in Cincinatti' had
no actual lyrics.
Led Zeppelin's
'Stairway To Heaven' despite it's popularity has never been
released as a single.

The 'Saturday Night Fever' Soundtrack was
the biggest selling soundtrack of all time until the mid 1990's
when 'The Bodyguard' soundtrack was released.