In 2000, bass player Jeroen Vierdag (1976) graduated cum laude from  the Conservatorium van  Amsterdam. He plays the bass guitar as well as the double bass in a wide variety of styles, such as pop, jazz, Brazilian and latin. Fifteen years ago, his career took off when he released the CD Live in Amsterdam, together with drummer Lucas van Merwijk and guitarist Leonardo Amuedo. Since then he has played and toured with many artists from the Dutch music scene such as Trijntje Oosterhuis, Alain Clark and Ilse de Lange.

Currently he is a member of The Ploctones (with Anton Goudsmit) and he plays with Francien van Tuinen, Amina Figarova, Bart Wirtz, Nueva Manteca and Caro Emerald. He is also a teacher at the Jazz and Latin Department at the Rotterdam Conservatory and the Jazz Department at the Conservatorium van Amsterdam. His versatility and flexibility make him a much sought-after bass player.