Waterfalls was the follow-up to the hit from what solo album?
Waterfalls (Paul McCartney song):  In the US, however, it was his first single ever to miss the "Billboard" Hot 100 chart, only reaching number 106 despite being the follow-up to the number one hit "Coming Up". Coming Up (song):  It is the opening track on his 1980 solo album "McCartney II".
McCartney II