Quartets - Chord of Appeal
Quartet "Chord of Appeal" (Peter Mason, Ross McMillan, Berry Knuvers, Richard Lewis) at the Pan Pacific Convention, Brisbane 2011. Chord of Appeal won a gold medal in the New Zealand Seniors competition and a silver medal in the Pan Pacific seniors competition.
Many see quartet singing (and especially quartet contests) as the pinnacle of the barbershop experience. Certainly, more experience is required - there is "nowhere to hide" in a quartet, as there are no longer 20 other singers also singing your part.
City of Sails generally has anything from one to five quartets going at any one time.