Andy Gibb was the younger brother of Barry, Robin and Maurice Gibb - the Bee Gees - but due to the age difference between Andy and his older brothers, and the fact that Andy didn't embrace disco to quite the degree that they did, Andy seldom performed with the Bee Gees, although they did help him write many of his songs, including this one.
Together, the brothers Gibb dominated the US pop chart in 1978, with Andy and the Bee Gees each scoring three #1 hits - and the Bee Gees contributing to a few others - but "Shadow Dancing" turned out to be the biggest of them all, staying at #1 for seven weeks and becoming Billboard
magazine's #1 single of the entire year of 1978. (Debby Boone's "You Light Up My Life
" was actually an even bigger hit, but because its chart run straddled 1977 and 1978, it only managed to finish #3 for 1978, behind the Bee Gees' "Night Fever").
Andy's other #1 hits in 1978 (both of which came before "Shadow Dancing") were "I Just Want To Be Your Everything" and "Love Is Thicker Than Water." He would also have a Top 5 hit that year with "An Everlasting Love." He was barely 20 years old at this, the height of his career.