The Bee Gees release Main Course

Working with Atlantic producer Arif Mardin, who had also produced their previous album, Mr. Natural, and engineer Karl Richardson at Criteria Studios in Miami, their music became much more influenced by dance music, primarily the Caribbean-styled disco being produced in Miami at the time. Main Course also featured the first prominent use of Barry Gibb's falsetto. The album cover was designed by US artist Drew Struzan.

From Mr. Natural, the brothers retained new drummer Dennis Bryon and longtime lead guitarist Alan Kendall but added a new keyboard player in the form of Bryon's former Mott the Hoople colleague Blue Weaver who would become one of only a small handful of non-Gibb musicians to receive composition credits on Bee Gees songs.

The sound became more technological with the use of synthesizers and dual bass lines (synthesizer bass by Blue Weaver and bass guitar by Maurice Gibb) on many of the songs, which came about after Weaver overdubbed a synthesizer bass line on the original demo of "Jive Talkin'." Weaver later commented that "nothing new has been invented to make such a tremendous difference to the sound as the synthesizer did, compared to an orchestra."
The album peaked at #14 on the U.S. Billboard album chart. Three singles from the album charted on Billboard's single chart: "Fanny (Be Tender with My Love)" at #12, "Nights on Broadway" at #7, and "Jive Talkin'" at #1. A live version of a fourth song, "Edge of the Universe" from the album Here At Last... Bee Gees Live, reached #26. "Come On Over" later became a moderate hit (#23) in a cover version by country/pop artist Olivia Newton-John.

http://en.wikipedia.org/wiki/Main_Course#History