Both before and after Saturday Night Fever, the brothers Gibb were more than disco hit machines. “Marley Purt Drive” from 1969 is an evocative country lament with sighing pedal steel and clucking banjo, while 1971's “Lion in Winter” is built around an insistent beat and Barry Gibb's soulful wail. Then fast-forward to Robin Gibb's slinky '80s solo turn on “Another Lonely Night In New York.”