pop-rock like Bon Jovi. Ritchie Sambora's harmony, jumping range from 5ths to 3rds harmony notes. good example for single voice backup.
acid jazz / funk eg: 'Incognito - Still a friend of mine' [3 or more voices], the 7th/9th voicings here.
also there may be a voice that stays the note [ chord sensitive], for 1-3 bars before changing. eg: 'i'll be over you - Toto'. the 3rd voice stays thru out on 'F', his role is the 5th on Bb, stays on to take 7th role on Gmin then changes 'Eb' to high root Eb. the lead vox will be on lower Bb then....
if you cant replicate the exact value of the lead vox sustain, then the harmony section should 'smartly' cut off the note collectively, at the bar end/last word.
hope it helps.