In 1959 the band, now called 'Peter and his Rockets', was joined by saxophone player Klaus Buchholz and bass guitarist Karel Jansen. In December, the band recorded "Kom Van Dat Dak Af" for record company Bovema. The combination of American rock and roll and Dutch lyrics was quite revolutionary at the time. In May 1960, "Kom Van Dat Dak Af" was a massive success in both the Netherlands and Belgium. Koelewijn, who moved on to grammar school, was told by his parents that he had to finish his schooling. Peter and His Rockets signed at Philips.