This track is an early example of what is now termed "Smooth Soul." Through the '50s and '60s, if you sang R&B or Soul, this is the sound you were compared to and sought to perfect. Later groups featuring a similar sound, from the '60s thru the '80s, would include The Spinners, Stylistics, Ace Spectrum, Blue Magic,etc.
Contemporary rivals included The Spanials, Dells, Channels, Drifters, Fandangos, and others.
The clip The Flamingos — I Only Have Eyes for You can be downloaded for free and without registration.