Search Result for "barbershop quartet":
Wordnet 3.0

NOUN (1)

1. an unaccompanied quartet of (usually male) voices singing sentimental songs in four-part harmony; 



WordNet (r) 3.0 (2006):

barbershop quartet
    n 1: an unaccompanied quartet of (usually male) voices singing
         sentimental songs in four-part harmony