The vocals are not sampled. Many singers have blessed the Koop albums with their talent. On the album Koop Islands the singers are : Yukimi Nagano, Ane Brun, Hilde Louise Asbjornsen, Earl Zinger and Mikael Sundin.
When playing live, Koop's main mission is to make people move their feet. The band transforms into a 7-9 piece swing orchestra including one or two singers and the line-up varies from time to time. Koop themselves play piano/accordion (Oscar), sampler (Magnus) and wear dresses.
Koop won a swedish grammy in 2003, and received a gold record for swedish sales of their last album "Koop Islands".